diff --git a/examples/dem/collapsing_sand_pile_3d.jl b/examples/dem/collapsing_sand_pile_3d.jl
index feb2510fd..457134ce9 100644
--- a/examples/dem/collapsing_sand_pile_3d.jl
+++ b/examples/dem/collapsing_sand_pile_3d.jl
@@ -51,7 +51,8 @@ min_coords_floor = (min_boundary[1] - boundary_thickness,
 floor_particles = RectangularShape(particle_spacing,
                                    (n_particles_floor_x, n_particles_floor_y,
                                     n_particles_floor_z),
-                                   min_coords_floor; density=boundary_density, tlsph=true)
+                                   min_coords_floor; density=boundary_density,
+                                   place_on_shell=true)
 boundary_particles = floor_particles
 
 # ==========================================================================================
diff --git a/examples/fsi/dam_break_gate_2d.jl b/examples/fsi/dam_break_gate_2d.jl
index 487857c05..654f5016e 100644
--- a/examples/fsi/dam_break_gate_2d.jl
+++ b/examples/fsi/dam_break_gate_2d.jl
@@ -75,18 +75,18 @@ solid_particle_spacing = thickness / (n_particles_x - 1)
 n_particles_y = round(Int, length_beam / solid_particle_spacing) + 1
 
 # The bottom layer is sampled separately below. Note that the `RectangularShape` puts the
-# first particle half a particle spacing away from the boundary, which is correct for fluids,
-# but not for solids. We therefore need to pass `tlsph=true`.
+# first particle half a particle spacing away from the shell of the shape, which is
+# correct for fluids, but not for solids. We therefore need to pass `place_on_shell=true`.
 #
 # The right end of the plate is 0.2 from the right end of the tank.
 plate_position = 0.6 - n_particles_x * solid_particle_spacing
 plate = RectangularShape(solid_particle_spacing,
                          (n_particles_x, n_particles_y - 1),
                          (plate_position, solid_particle_spacing),
-                         density=solid_density, tlsph=true)
+                         density=solid_density, place_on_shell=true)
 fixed_particles = RectangularShape(solid_particle_spacing,
                                    (n_particles_x, 1), (plate_position, 0.0),
-                                   density=solid_density, tlsph=true)
+                                   density=solid_density, place_on_shell=true)
 
 solid = union(plate, fixed_particles)
 
diff --git a/examples/fsi/dam_break_plate_2d.jl b/examples/fsi/dam_break_plate_2d.jl
index 4ac1a4a08..7b1ca18b7 100644
--- a/examples/fsi/dam_break_plate_2d.jl
+++ b/examples/fsi/dam_break_plate_2d.jl
@@ -51,15 +51,15 @@ solid_particle_spacing = thickness / (n_particles_x - 1)
 n_particles_y = round(Int, length_beam / solid_particle_spacing) + 1
 
 # The bottom layer is sampled separately below. Note that the `RectangularShape` puts the
-# first particle half a particle spacing away from the boundary, which is correct for fluids,
-# but not for solids. We therefore need to pass `tlsph=true`.
+# first particle half a particle spacing away from the shell of the shape, which is
+# correct for fluids, but not for solids. We therefore need to pass `place_on_shell=true`.
 plate = RectangularShape(solid_particle_spacing,
                          (n_particles_x, n_particles_y - 1),
                          (2initial_fluid_size[1], solid_particle_spacing),
-                         density=solid_density, tlsph=true)
+                         density=solid_density, place_on_shell=true)
 fixed_particles = RectangularShape(solid_particle_spacing,
                                    (n_particles_x, 1), (2initial_fluid_size[1], 0.0),
-                                   density=solid_density, tlsph=true)
+                                   density=solid_density, place_on_shell=true)
 
 solid = union(plate, fixed_particles)
 
diff --git a/examples/preprocessing/packing_2d.jl b/examples/preprocessing/packing_2d.jl
index b26f95057..85227dc10 100644
--- a/examples/preprocessing/packing_2d.jl
+++ b/examples/preprocessing/packing_2d.jl
@@ -6,7 +6,7 @@ file = pkgdir(TrixiParticles, "examples", "preprocessing", "data", filename * ".
 
 # ==========================================================================================
 # ==== Packing parameters
-tlsph = false
+place_on_shell = false
 
 # ==========================================================================================
 # ==== Resolution
@@ -36,7 +36,7 @@ shape_sampled = ComplexShape(geometry; particle_spacing, density,
 
 # Returns `InitialCondition`
 boundary_sampled = sample_boundary(signed_distance_field; boundary_density=density,
-                                   boundary_thickness, tlsph=tlsph)
+                                   boundary_thickness, place_on_shell=place_on_shell)
 
 trixi2vtk(shape_sampled)
 trixi2vtk(boundary_sampled, filename="boundary")
@@ -52,12 +52,13 @@ background_pressure = 1.0
 
 smoothing_length = 0.8 * particle_spacing
 packing_system = ParticlePackingSystem(shape_sampled; smoothing_length=smoothing_length,
-                                       signed_distance_field, tlsph=tlsph,
+                                       signed_distance_field, place_on_shell=place_on_shell,
                                        background_pressure)
 
 boundary_system = ParticlePackingSystem(boundary_sampled; smoothing_length=smoothing_length,
                                         is_boundary=true, signed_distance_field,
-                                        tlsph=tlsph, boundary_compress_factor=0.8,
+                                        place_on_shell=place_on_shell,
+                                        boundary_compress_factor=0.8,
                                         background_pressure)
 
 # ==========================================================================================
diff --git a/examples/preprocessing/packing_3d.jl b/examples/preprocessing/packing_3d.jl
index 0331d3c0a..0ca9bf7d8 100644
--- a/examples/preprocessing/packing_3d.jl
+++ b/examples/preprocessing/packing_3d.jl
@@ -15,5 +15,5 @@ boundary_thickness = 8 * particle_spacing
 
 trixi_include(joinpath(examples_dir(), "preprocessing", "packing_2d.jl"),
               density=1000.0, particle_spacing=particle_spacing, file=file,
-              boundary_thickness=boundary_thickness, tlsph=true,
+              boundary_thickness=boundary_thickness, place_on_shell=true,
               save_intervals=false)
diff --git a/examples/solid/oscillating_beam_2d.jl b/examples/solid/oscillating_beam_2d.jl
index 15ad8c99e..aa25f64c2 100644
--- a/examples/solid/oscillating_beam_2d.jl
+++ b/examples/solid/oscillating_beam_2d.jl
@@ -23,7 +23,7 @@ fixed_particles = SphereShape(particle_spacing, clamp_radius + particle_spacing
                               (0.0, elastic_beam.thickness / 2), material.density,
                               cutout_min=(0.0, 0.0),
                               cutout_max=(clamp_radius, elastic_beam.thickness),
-                              tlsph=true)
+                              place_on_shell=true)
 
 n_particles_clamp_x = round(Int, clamp_radius / particle_spacing)
 
@@ -33,9 +33,9 @@ n_particles_per_dimension = (round(Int, elastic_beam.length / particle_spacing)
 
 # Note that the `RectangularShape` puts the first particle half a particle spacing away
 # from the boundary, which is correct for fluids, but not for solids.
-# We therefore need to pass `tlsph=true`.
+# We therefore need to pass `place_on_shell=true`.
 beam = RectangularShape(particle_spacing, n_particles_per_dimension,
-                        (0.0, 0.0), density=material.density, tlsph=true)
+                        (0.0, 0.0), density=material.density, place_on_shell=true)
 
 solid = union(beam, fixed_particles)
 
diff --git a/src/general/interpolation.jl b/src/general/interpolation.jl
index 9b0ac40d7..6ca3fa16f 100644
--- a/src/general/interpolation.jl
+++ b/src/general/interpolation.jl
@@ -191,9 +191,10 @@ function interpolate_plane_2d(min_corner, max_corner, resolution, semi, ref_syst
     x_range = range(min_corner[1], max_corner[1], length=n_points_per_dimension[1])
     y_range = range(min_corner[2], max_corner[2], length=n_points_per_dimension[2])
 
-    # Generate points within the plane. Use `tlsph=true` to generate points on the boundary
+    # Generate points within the plane. Use `place_on_shell=true` to generate points
+    # on the shell of the geometry.
     point_coords = rectangular_shape_coords(resolution, n_points_per_dimension, min_corner,
-                                            tlsph=true)
+                                            place_on_shell=true)
 
     results = interpolate_points(point_coords, semi, ref_system, v_ode, u_ode,
                                  smoothing_length=smoothing_length,
diff --git a/src/preprocessing/particle_packing/signed_distance.jl b/src/preprocessing/particle_packing/signed_distance.jl
index 7e957e124..082deced5 100644
--- a/src/preprocessing/particle_packing/signed_distance.jl
+++ b/src/preprocessing/particle_packing/signed_distance.jl
@@ -59,7 +59,7 @@ function SignedDistanceField(geometry, particle_spacing;
                                                 particle_spacing))
 
         grid = rectangular_shape_coords(particle_spacing, n_particles_per_dimension,
-                                        min_corner; tlsph=true)
+                                        min_corner; place_on_shell=true)
 
         points = reinterpret(reshape, SVector{NDIMS, ELTYPE}, grid)
     end
diff --git a/src/preprocessing/particle_packing/system.jl b/src/preprocessing/particle_packing/system.jl
index be6697fb1..f91336036 100644
--- a/src/preprocessing/particle_packing/system.jl
+++ b/src/preprocessing/particle_packing/system.jl
@@ -6,7 +6,7 @@
                           smoothing_length_interpolation=smoothing_length,
                           is_boundary=false, boundary_compress_factor=1,
                           neighborhood_search=GridNeighborhoodSearch{ndims(shape)}(),
-                          background_pressure, tlsph=false, fixed_system=false)
+                          background_pressure, place_on_shell=false, fixed_system=false)
 
 System to generate body-fitted particles for complex shapes.
 For more information on the methods, see [particle packing](@ref particle_packing).
@@ -18,10 +18,11 @@ For more information on the methods, see [particle packing](@ref particle_packin
 - `background_pressure`:   Constant background pressure to physically pack the particles.
                            A large `background_pressure` can cause high accelerations
                            which requires a properly adjusted time step.
-- `tlsph`:                 With the [`TotalLagrangianSPHSystem`](@ref), particles need to be placed
-                           on the boundary of the shape and not half a particle spacing away,
-                           as for fluids. When `tlsph=true`, particles will be placed
-                           on the boundary of the shape.
+- `place_on_shell`:        If `place_on_shell=true`, particles will be placed
+                           on the shell of the geometry. For example,
+                           the [`TotalLagrangianSPHSystem`](@ref) requires particles to be placed
+                           on the shell of the geometry and not half a particle spacing away,
+                           as for fluids.
 - `is_boundary`:           When `shape` is inside the geometry that was used to create
                            `signed_distance_field`, set `is_boundary=false`.
                            Otherwise (`shape` is the sampled boundary), set `is_boundary=true`.
@@ -64,7 +65,7 @@ struct ParticlePackingSystem{S, F, NDIMS, ELTYPE <: Real, PR, C, AV,
     smoothing_kernel               :: K
     smoothing_length_interpolation :: ELTYPE
     background_pressure            :: ELTYPE
-    tlsph                          :: Bool
+    place_on_shell                 :: Bool
     signed_distance_field          :: S
     is_boundary                    :: Bool
     shift_length                   :: ELTYPE
@@ -79,7 +80,8 @@ struct ParticlePackingSystem{S, F, NDIMS, ELTYPE <: Real, PR, C, AV,
     # See the comments in general/gpu.jl for more details.
     function ParticlePackingSystem(initial_condition, mass, density, particle_spacing,
                                    smoothing_kernel, smoothing_length_interpolation,
-                                   background_pressure, tlsph, signed_distance_field,
+                                   background_pressure, place_on_shell,
+                                   signed_distance_field,
                                    is_boundary, shift_length, neighborhood_search,
                                    signed_distances, particle_refinement, buffer,
                                    update_callback_used, fixed_system, cache,
@@ -93,7 +95,7 @@ struct ParticlePackingSystem{S, F, NDIMS, ELTYPE <: Real, PR, C, AV,
                                                  mass, density, particle_spacing,
                                                  smoothing_kernel,
                                                  smoothing_length_interpolation,
-                                                 background_pressure, tlsph,
+                                                 background_pressure, place_on_shell,
                                                  signed_distance_field, is_boundary,
                                                  shift_length, neighborhood_search,
                                                  signed_distances, particle_refinement,
@@ -108,7 +110,8 @@ function ParticlePackingSystem(shape::InitialCondition;
                                smoothing_length_interpolation=smoothing_length,
                                is_boundary=false, boundary_compress_factor=1,
                                neighborhood_search=GridNeighborhoodSearch{ndims(shape)}(),
-                               background_pressure, tlsph=false, fixed_system=false)
+                               background_pressure, place_on_shell=false,
+                               fixed_system=false)
     NDIMS = ndims(shape)
     ELTYPE = eltype(shape)
     mass = copy(shape.mass)
@@ -147,12 +150,12 @@ function ParticlePackingSystem(shape::InitialCondition;
     # Its value is negative if the particle is inside the geometry.
     # Otherwise (if outside), the value is positive.
     if is_boundary
-        offset = tlsph ? shape.particle_spacing : shape.particle_spacing / 2
+        offset = place_on_shell ? shape.particle_spacing : shape.particle_spacing / 2
 
         shift_length = -boundary_compress_factor *
                        signed_distance_field.max_signed_distance - offset
     else
-        shift_length = tlsph ? zero(ELTYPE) : shape.particle_spacing / 2
+        shift_length = place_on_shell ? zero(ELTYPE) : shape.particle_spacing / 2
     end
 
     cache = (; create_cache_refinement(shape, particle_refinement, smoothing_length)...)
@@ -161,7 +164,7 @@ function ParticlePackingSystem(shape::InitialCondition;
 
     return ParticlePackingSystem(shape, mass, density, shape.particle_spacing,
                                  smoothing_kernel, smoothing_length_interpolation,
-                                 background_pressure, tlsph, signed_distance_field,
+                                 background_pressure, place_on_shell, signed_distance_field,
                                  is_boundary, shift_length, nhs,
                                  fill(zero(ELTYPE), nparticles(shape)), particle_refinement,
                                  nothing, Ref(false), fixed_system, cache,
@@ -187,7 +190,7 @@ function Base.show(io::IO, ::MIME"text/plain", system::ParticlePackingSystem)
                      system.neighborhood_search |> typeof |> nameof)
         summary_line(io, "#particles", nparticles(system))
         summary_line(io, "smoothing kernel", system.smoothing_kernel |> typeof |> nameof)
-        summary_line(io, "tlsph", system.tlsph ? "yes" : "no")
+        summary_line(io, "place_on_shell", system.place_on_shell ? "yes" : "no")
         summary_line(io, "boundary", system.is_boundary ? "yes" : "no")
         summary_footer(io)
     end
@@ -349,8 +352,8 @@ function constrain_particle!(u, system, particle, distance_signed, normal_vector
     (; shift_length) = system
 
     # For fluid particles:
-    # - `tlsph = true`: `shift_length = 0`
-    # - `tlsph = false`: `shift_length = particle_spacing / 2`
+    # - `place_on_shell = true`: `shift_length = 0`
+    # - `place_on_shell = false`: `shift_length = particle_spacing / 2`
     # For boundary particles:
     # `shift_length` is the thickness of the boundary.
     if distance_signed >= -shift_length
@@ -365,7 +368,7 @@ function constrain_particle!(u, system, particle, distance_signed, normal_vector
     system.is_boundary || return u
 
     particle_spacing = system.initial_condition.particle_spacing
-    shift_length_inner = system.tlsph ? particle_spacing : particle_spacing / 2
+    shift_length_inner = system.place_on_shell ? particle_spacing : particle_spacing / 2
 
     if distance_signed < shift_length_inner
         shift = (distance_signed - shift_length_inner) * normal_vector
diff --git a/src/setups/complex_shape.jl b/src/setups/complex_shape.jl
index 2c515157d..594b3b4f3 100644
--- a/src/setups/complex_shape.jl
+++ b/src/setups/complex_shape.jl
@@ -79,7 +79,7 @@ end
 
 """
     sample_boundary(signed_distance_field::SignedDistanceField;
-                    boundary_thickness::Real, tlsph=true)
+                    boundary_thickness::Real, place_on_shell=true)
 
 Sample boundary particles of a complex geometry by using the [`SignedDistanceField`](@ref)
 of the geometry.
@@ -89,9 +89,9 @@ of the geometry.
 
 # Keywords
 - `boundary_thickness`: Thickness of the boundary
-- `tlsph`             : When `tlsph=true`, boundary particles will be placed
+- `place_on_shell`:     When `place_on_shell=true`, boundary particles will be placed
                         one particle spacing from the surface of the geometry.
-                        Otherwise when `tlsph=true` (simulating fluid particles),
+                        Otherwise when `place_on_shell=true` (simulating fluid particles),
                         boundary particles will be placed half particle spacing away from the surface.
 
 
@@ -117,7 +117,7 @@ boundary_sampled = sample_boundary(signed_distance_field; boundary_density=1.0,
 ```
 """
 function sample_boundary(signed_distance_field;
-                         boundary_density, boundary_thickness, tlsph=true)
+                         boundary_density, boundary_thickness, place_on_shell=true)
     (; max_signed_distance, boundary_packing,
      positions, distances, particle_spacing) = signed_distance_field
 
@@ -157,6 +157,6 @@ function particle_grid(geometry, particle_spacing;
     end
 
     grid = rectangular_shape_coords(particle_spacing, n_particles_per_dimension,
-                                    min_corner; tlsph=true)
+                                    min_corner; place_on_shell=true)
     return reinterpret(reshape, SVector{ndims(geometry), eltype(geometry)}, grid)
 end
diff --git a/src/setups/extrude_geometry.jl b/src/setups/extrude_geometry.jl
index 498266ecd..6d169762c 100644
--- a/src/setups/extrude_geometry.jl
+++ b/src/setups/extrude_geometry.jl
@@ -30,9 +30,11 @@ Returns an [`InitialCondition`](@ref).
 - `pressure`:           Scalar to set the pressure of all particles to this value.
                         This is only used by the [`EntropicallyDampedSPHSystem`](@ref) and
                         will be overwritten when using an initial pressure function in the system.
-- `tlsph`:              With the [`TotalLagrangianSPHSystem`](@ref), particles need to be placed
-                        on the boundary of the shape and not one particle radius away, as for fluids.
-                        When `tlsph=true`, particles will be placed on the boundary of the shape.
+- `place_on_shell`:     If `place_on_shell=true`, particles will be placed
+                        on the shell of the geometry. For example,
+                        the [`TotalLagrangianSPHSystem`](@ref) requires particles to be placed
+                        on the shell of the geometry and not half a particle spacing away,
+                        as for fluids.
 
 # Examples
 ```jldoctest; output = false
@@ -79,7 +81,7 @@ shape = extrude_geometry(shape; direction, particle_spacing=0.1, n_extrude=4, de
     This is an experimental feature and may change in any future releases.
 """
 function extrude_geometry(geometry; particle_spacing=-1, direction, n_extrude::Integer,
-                          velocity=zeros(length(direction)), tlsph=false,
+                          velocity=zeros(length(direction)), place_on_shell=false,
                           mass=nothing, density=nothing, pressure=0.0)
     direction_ = normalize(direction)
     NDIMS = length(direction_)
@@ -95,9 +97,11 @@ function extrude_geometry(geometry; particle_spacing=-1, direction, n_extrude::I
         throw(ArgumentError("`particle_spacing` must be specified when not extruding an `InitialCondition`"))
     end
 
-    geometry = shift_plane_corners(geometry, direction_, particle_spacing, tlsph)
+    geometry = shift_plane_corners(geometry, direction_, particle_spacing, place_on_shell)
 
-    face_coords, particle_spacing_ = sample_plane(geometry, particle_spacing; tlsph=tlsph)
+    face_coords,
+    particle_spacing_ = sample_plane(geometry, particle_spacing;
+                                     place_on_shell=place_on_shell)
 
     if !isapprox(particle_spacing, particle_spacing_, rtol=5e-2)
         @info "The desired size is not a multiple of the particle spacing $particle_spacing." *
@@ -119,12 +123,13 @@ end
 
 # For corners/endpoints of a plane/line, sample the plane/line with particles.
 # For 2D coordinates or an `InitialCondition`, add a third dimension.
-function sample_plane(geometry::AbstractMatrix, particle_spacing; tlsph)
+function sample_plane(geometry::AbstractMatrix, particle_spacing; place_on_shell)
     if size(geometry, 1) == 2
         # Extruding a 2D shape results in a 3D shape
 
-        # When `tlsph=true`, particles will be placed on the x-y plane
-        coords = vcat(geometry, fill(tlsph ? 0 : particle_spacing / 2, size(geometry, 2))')
+        # When `place_on_shell=true`, particles will be placed on the x-y plane
+        coords = vcat(geometry,
+                      fill(place_on_shell ? 0 : particle_spacing / 2, size(geometry, 2))')
 
         # TODO: 2D shapes not only in x-y plane but in any user-defined plane
         return coords, particle_spacing
@@ -133,13 +138,14 @@ function sample_plane(geometry::AbstractMatrix, particle_spacing; tlsph)
     return geometry, particle_spacing
 end
 
-function sample_plane(shape::InitialCondition, particle_spacing; tlsph)
+function sample_plane(shape::InitialCondition, particle_spacing; place_on_shell)
     if ndims(shape) == 2
         # Extruding a 2D shape results in a 3D shape
 
-        # When `tlsph=true`, particles will be placed on the x-y plane
+        # When `place_on_shell=true`, particles will be placed on the x-y plane
         coords = vcat(shape.coordinates,
-                      fill(tlsph ? 0 : particle_spacing / 2, size(shape.coordinates, 2))')
+                      fill(place_on_shell ? 0 : particle_spacing / 2,
+                           size(shape.coordinates, 2))')
 
         # TODO: 2D shapes not only in x-y plane but in any user-defined plane
         return coords, particle_spacing
@@ -148,13 +154,13 @@ function sample_plane(shape::InitialCondition, particle_spacing; tlsph)
     return shape.coordinates, particle_spacing
 end
 
-function sample_plane(plane_points, particle_spacing; tlsph=nothing)
+function sample_plane(plane_points, particle_spacing; place_on_shell=nothing)
 
     # Convert to tuple
-    return sample_plane(tuple(plane_points...), particle_spacing; tlsph=nothing)
+    return sample_plane(tuple(plane_points...), particle_spacing; place_on_shell=nothing)
 end
 
-function sample_plane(plane_points::NTuple{2}, particle_spacing; tlsph=nothing)
+function sample_plane(plane_points::NTuple{2}, particle_spacing; place_on_shell=nothing)
     # Verify that points are in 2D space
     if any(length.(plane_points) .!= 2)
         throw(ArgumentError("all points must be 2D coordinates"))
@@ -168,7 +174,7 @@ function sample_plane(plane_points::NTuple{2}, particle_spacing; tlsph=nothing)
     return coords, particle_spacing_new
 end
 
-function sample_plane(plane_points::NTuple{3}, particle_spacing; tlsph=nothing)
+function sample_plane(plane_points::NTuple{3}, particle_spacing; place_on_shell=nothing)
     # Verify that points are in 3D space
     if any(length.(plane_points) .!= 3)
         throw(ArgumentError("all points must be 3D coordinates"))
@@ -209,21 +215,22 @@ function sample_plane(plane_points::NTuple{3}, particle_spacing; tlsph=nothing)
     return coords, particle_spacing_new
 end
 
-# Shift corners of the plane/line inwards by half a particle spacing with `tlsph=false`
+# Shift corners of the plane/line inwards by half a particle spacing with `place_on_shell=false`
 # because fluid particles need to be half a particle spacing away from the boundary of the shape.
 function shift_plane_corners(geometry::Union{AbstractMatrix, InitialCondition},
-                             direction, particle_spacing, tlsph)
+                             direction, particle_spacing, place_on_shell)
     return geometry
 end
 
-function shift_plane_corners(plane_points, direction, particle_spacing, tlsph)
-    shift_plane_corners(tuple(plane_points...), direction, particle_spacing, tlsph)
+function shift_plane_corners(plane_points, direction, particle_spacing, place_on_shell)
+    shift_plane_corners(tuple(plane_points...), direction, particle_spacing, place_on_shell)
 end
 
-function shift_plane_corners(plane_points::NTuple{2}, direction, particle_spacing, tlsph)
-    # With TLSPH, particles need to be AT the min coordinates and not half a particle
+function shift_plane_corners(plane_points::NTuple{2}, direction, particle_spacing,
+                             place_on_shell)
+    # With `place_on_shell`, particles need to be AT the min coordinates and not half a particle
     # spacing away from it.
-    (tlsph) && (return plane_points)
+    (place_on_shell) && (return plane_points)
 
     plane_point1 = copy(plane_points[1])
     plane_point2 = copy(plane_points[2])
@@ -238,10 +245,11 @@ function shift_plane_corners(plane_points::NTuple{2}, direction, particle_spacin
     return (plane_point1, plane_point2)
 end
 
-function shift_plane_corners(plane_points::NTuple{3}, direction, particle_spacing, tlsph)
-    # With TLSPH, particles need to be AT the min coordinates and not half a particle
+function shift_plane_corners(plane_points::NTuple{3}, direction, particle_spacing,
+                             place_on_shell)
+    # With `place_on_shell`, particles need to be AT the min coordinates and not half a particle
     # spacing away from it.
-    (tlsph) && (return plane_points)
+    (place_on_shell) && (return plane_points)
 
     plane_point1 = copy(plane_points[1])
     plane_point2 = copy(plane_points[2])
diff --git a/src/setups/rectangular_shape.jl b/src/setups/rectangular_shape.jl
index 98160bcac..1c30ef5c1 100644
--- a/src/setups/rectangular_shape.jl
+++ b/src/setups/rectangular_shape.jl
@@ -3,7 +3,7 @@
                      velocity=zeros(length(n_particles_per_dimension)),
                      mass=nothing, density=nothing, pressure=0.0,
                      acceleration=nothing, state_equation=nothing,
-                     tlsph=false, loop_order=nothing)
+                     place_on_shell=false, loop_order=nothing)
 
 Rectangular shape filled with particles. Returns an [`InitialCondition`](@ref).
 
@@ -40,9 +40,10 @@ Rectangular shape filled with particles. Returns an [`InitialCondition`](@ref).
 - `state_equation`: When calculating a hydrostatic pressure gradient by setting `acceleration`,
                     the `state_equation` will be used to set the corresponding density.
                     Cannot be used together with `density`.
-- `tlsph`:          With the [`TotalLagrangianSPHSystem`](@ref), particles need to be placed
-                    on the boundary of the shape and not one particle radius away, as for fluids.
-                    When `tlsph=true`, particles will be placed on the boundary of the shape.
+- `place_on_shell`: If `place_on_shell=true`, particles will be placed on the shell of the shape.
+                    For example, the [`TotalLagrangianSPHSystem`](@ref) requires particles
+                    to be placed on the shell of the shape and not half a particle spacing away,
+                    as for fluids.
 - `coordinates_perturbation`: Add a small random displacement to the particle positions,
                               where the amplitude is `coordinates_perturbation * particle_spacing`.
 
@@ -75,7 +76,7 @@ function RectangularShape(particle_spacing, n_particles_per_dimension, min_coord
                           coordinates_perturbation=nothing,
                           mass=nothing, density=nothing, pressure=0.0,
                           acceleration=nothing, state_equation=nothing,
-                          tlsph=false, loop_order=nothing)
+                          place_on_shell=false, loop_order=nothing)
     if particle_spacing < eps()
         throw(ArgumentError("`particle_spacing` needs to be positive and larger than $(eps())"))
     end
@@ -95,7 +96,7 @@ function RectangularShape(particle_spacing, n_particles_per_dimension, min_coord
     n_particles = prod(n_particles_per_dimension)
 
     coordinates = rectangular_shape_coords(particle_spacing, n_particles_per_dimension,
-                                           min_coordinates, tlsph=tlsph,
+                                           min_coordinates, place_on_shell=place_on_shell,
                                            loop_order=loop_order)
 
     if !isnothing(coordinates_perturbation)
@@ -190,15 +191,15 @@ function loop_permutation(loop_order, NDIMS::Val{3})
 end
 
 function rectangular_shape_coords(particle_spacing, n_particles_per_dimension,
-                                  min_coordinates; tlsph=false, loop_order=nothing)
+                                  min_coordinates; place_on_shell=false, loop_order=nothing)
     ELTYPE = eltype(particle_spacing)
     NDIMS = length(n_particles_per_dimension)
 
     coordinates = Array{ELTYPE, 2}(undef, NDIMS, prod(n_particles_per_dimension))
 
-    # With TLSPH, particles need to be AT the min coordinates and not half a particle
+    # With place_on_shell, particles need to be AT the min coordinates and not half a particle
     # spacing away from it.
-    if tlsph
+    if place_on_shell
         min_coordinates = min_coordinates .- 0.5particle_spacing
     end
 
diff --git a/src/setups/sphere_shape.jl b/src/setups/sphere_shape.jl
index 0233fc899..3c6a7466d 100644
--- a/src/setups/sphere_shape.jl
+++ b/src/setups/sphere_shape.jl
@@ -1,7 +1,7 @@
 """
     SphereShape(particle_spacing, radius, center_position, density;
                 sphere_type=VoxelSphere(), n_layers=-1, layer_outwards=false,
-                cutout_min=(0.0, 0.0), cutout_max=(0.0, 0.0), tlsph=false,
+                cutout_min=(0.0, 0.0), cutout_max=(0.0, 0.0), place_on_shell=false,
                 velocity=zeros(length(center_position)), mass=nothing, pressure=0.0)
 
 Generate a sphere that is either completely filled (by default)
@@ -35,18 +35,19 @@ coordinate directions as `cutout_min` and `cutout_max`.
                     cut out of the sphere.
 - `cutout_max`:     Corner in positive coordinate directions of a cuboid that is to be
                     cut out of the sphere.
-- `tlsph`:          With the [`TotalLagrangianSPHSystem`](@ref), particles need to be placed
-                    on the boundary of the shape and not one particle radius away, as for fluids.
-                    When `tlsph=true`, particles will be placed on the boundary of the shape.
-- `velocity`:   Either a function mapping each particle's coordinates to its velocity,
-                or, for a constant fluid velocity, a vector holding this velocity.
-                Velocity is constant zero by default.
-- `mass`:       Either `nothing` (default) to automatically compute particle mass from particle
-                density and spacing, or a function mapping each particle's coordinates to its mass,
-                or a scalar for a constant mass over all particles.
-- `pressure`:   Either a function mapping each particle's coordinates to its pressure,
-                or a scalar for a constant pressure over all particles. This is optional and
-                only needed when using the [`EntropicallyDampedSPHSystem`](@ref).
+- `place_on_shell`: If `place_on_shell=true`, particles will be placed on the shell of the shape.
+                    For example, the [`TotalLagrangianSPHSystem`](@ref) requires particles
+                    to be placed on the shell of the shape and not half a particle spacing away,
+                    as for fluids.
+- `velocity`:       Either a function mapping each particle's coordinates to its velocity,
+                    or, for a constant fluid velocity, a vector holding this velocity.
+                    Velocity is constant zero by default.
+- `mass`:           Either `nothing` (default) to automatically compute particle mass from particle
+                    density and spacing, or a function mapping each particle's coordinates to its mass,
+                    or a scalar for a constant mass over all particles.
+- `pressure`:       Either a function mapping each particle's coordinates to its pressure,
+                    or a scalar for a constant pressure over all particles. This is optional and
+                    only needed when using the [`EntropicallyDampedSPHSystem`](@ref).
 
 # Examples
 ```jldoctest; output = false
@@ -89,7 +90,7 @@ SphereShape(0.1, 0.5, (0.2, 0.4, 0.3), 1000.0, sphere_type=RoundSphere())
 """
 function SphereShape(particle_spacing, radius, center_position, density;
                      sphere_type=VoxelSphere(), n_layers=-1, layer_outwards=false,
-                     cutout_min=(0.0, 0.0), cutout_max=(0.0, 0.0), tlsph=false,
+                     cutout_min=(0.0, 0.0), cutout_max=(0.0, 0.0), place_on_shell=false,
                      velocity=zeros(length(center_position)), mass=nothing, pressure=0)
     if particle_spacing < eps()
         throw(ArgumentError("`particle_spacing` needs to be positive and larger than $(eps())"))
@@ -99,7 +100,7 @@ function SphereShape(particle_spacing, radius, center_position, density;
 
     coordinates = sphere_shape_coords(sphere_type, particle_spacing, radius,
                                       SVector{NDIMS}(center_position),
-                                      n_layers, layer_outwards, tlsph)
+                                      n_layers, layer_outwards, place_on_shell)
 
     # Convert tuples to vectors
     cutout_min_ = collect(cutout_min)
@@ -169,13 +170,13 @@ struct RoundSphere{AR}
 end
 
 function sphere_shape_coords(::VoxelSphere, particle_spacing, radius, center_position,
-                             n_layers, layer_outwards, tlsph)
+                             n_layers, layer_outwards, place_on_shell)
     if n_layers > 0
         if layer_outwards
             inner_radius = radius
             outer_radius = radius + n_layers * particle_spacing
 
-            if !tlsph
+            if !place_on_shell
                 # Put first layer of particles half a particle spacing outside of `radius`
                 inner_radius += particle_spacing / 2
                 outer_radius += particle_spacing / 2
@@ -184,7 +185,7 @@ function sphere_shape_coords(::VoxelSphere, particle_spacing, radius, center_pos
             inner_radius = radius - n_layers * particle_spacing
             outer_radius = radius
 
-            if !tlsph
+            if !place_on_shell
                 # Put first layer of particles half a particle spacing inside of `radius`
                 inner_radius -= particle_spacing / 2
                 outer_radius -= particle_spacing / 2
@@ -194,7 +195,7 @@ function sphere_shape_coords(::VoxelSphere, particle_spacing, radius, center_pos
         outer_radius = radius
         inner_radius = -1
 
-        if !tlsph
+        if !place_on_shell
             # Put first layer of particles half a particle spacing inside of `radius`
             outer_radius -= particle_spacing / 2
         end
@@ -225,7 +226,7 @@ function sphere_shape_coords(::VoxelSphere, particle_spacing, radius, center_pos
 end
 
 function sphere_shape_coords(sphere::RoundSphere, particle_spacing, radius, center,
-                             n_layers, layer_outwards, tlsph)
+                             n_layers, layer_outwards, place_on_shell)
     if n_layers > 0
         if layer_outwards
             inner_radius = radius
@@ -233,12 +234,12 @@ function sphere_shape_coords(sphere::RoundSphere, particle_spacing, radius, cent
             inner_radius = radius - n_layers * particle_spacing
         end
 
-        if !tlsph
+        if !place_on_shell
             # Put first layer of particles half a particle spacing outside of inner radius
             inner_radius += particle_spacing / 2
         end
     else
-        if tlsph
+        if place_on_shell
             # Just create a sphere that is 0.5 particle spacing larger
             radius += particle_spacing / 2
         end
diff --git a/test/setups/extrude_geometry.jl b/test/setups/extrude_geometry.jl
index e695f2e17..5a927dbee 100644
--- a/test/setups/extrude_geometry.jl
+++ b/test/setups/extrude_geometry.jl
@@ -28,7 +28,8 @@
         ]
 
         @testset "Direction $i" for i in eachindex(directions)
-            shape = extrude_geometry((point1, point2); direction=directions[i], tlsph=true,
+            shape = extrude_geometry((point1, point2); direction=directions[i],
+                                     place_on_shell=true,
                                      particle_spacing=0.15, n_extrude=5, density=1.0)
 
             @test shape.coordinates ≈ expected_coords[i]
@@ -68,7 +69,7 @@ end
 
         @testset "Direction $i" for i in eachindex(directions)
             shape = extrude_geometry(geometry; direction=directions[i], particle_spacing,
-                                     n_extrude=5, tlsph=true, density=1.0)
+                                     n_extrude=5, place_on_shell=true, density=1.0)
 
             @test shape.coordinates ≈ expected_coords[i]
         end
@@ -86,7 +87,7 @@ end
                            0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.06666666666666667 0.06666666666666667 0.06666666666666667 0.06666666666666667 0.06666666666666667 0.06666666666666667 0.06666666666666667 0.06666666666666667 0.06666666666666667 0.06666666666666667 0.06666666666666667 0.06666666666666667 0.13333333333333333 0.13333333333333333 0.13333333333333333 0.13333333333333333 0.13333333333333333 0.13333333333333333 0.13333333333333333 0.13333333333333333 0.13333333333333333 0.13333333333333333 0.13333333333333333 0.13333333333333333 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.26666666666666666 0.26666666666666666 0.26666666666666666 0.26666666666666666 0.26666666666666666 0.26666666666666666 0.26666666666666666 0.26666666666666666 0.26666666666666666 0.26666666666666666 0.26666666666666666 0.26666666666666666 0.3333333333333333 0.3333333333333333 0.3333333333333333 0.3333333333333333 0.3333333333333333 0.3333333333333333 0.3333333333333333 0.3333333333333333 0.3333333333333333 0.3333333333333333 0.3333333333333333 0.3333333333333333 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4666666666666667 0.4666666666666667 0.4666666666666667 0.4666666666666667 0.4666666666666667 0.4666666666666667 0.4666666666666667 0.4666666666666667 0.4666666666666667 0.4666666666666667 0.4666666666666667 0.4666666666666667 0.5333333333333333 0.5333333333333333 0.5333333333333333 0.5333333333333333 0.5333333333333333 0.5333333333333333 0.5333333333333333 0.5333333333333333 0.5333333333333333 0.5333333333333333 0.5333333333333333 0.5333333333333333 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6666666666666666 0.6666666666666666 0.6666666666666666 0.6666666666666666 0.6666666666666666 0.6666666666666666 0.6666666666666666 0.6666666666666666 0.6666666666666666 0.6666666666666666 0.6666666666666666 0.6666666666666666 0.7333333333333333 0.7333333333333333 0.7333333333333333 0.7333333333333333 0.7333333333333333 0.7333333333333333 0.7333333333333333 0.7333333333333333 0.7333333333333333 0.7333333333333333 0.7333333333333333 0.7333333333333333 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8666666666666667 0.8666666666666667 0.8666666666666667 0.8666666666666667 0.8666666666666667 0.8666666666666667 0.8666666666666667 0.8666666666666667 0.8666666666666667 0.8666666666666667 0.8666666666666667 0.8666666666666667 0.9333333333333333 0.9333333333333333 0.9333333333333333 0.9333333333333333 0.9333333333333333 0.9333333333333333 0.9333333333333333 0.9333333333333333 0.9333333333333333 0.9333333333333333 0.9333333333333333 0.9333333333333333 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.092709445701687 0.092709445701687 0.092709445701687 0.092709445701687 0.092709445701687 0.092709445701687 0.092709445701687 0.092709445701687 0.092709445701687 0.092709445701687 0.092709445701687 0.092709445701687 0.15937611236835367 0.15937611236835367 0.15937611236835367 0.15937611236835367 0.15937611236835367 0.15937611236835367 0.15937611236835367 0.15937611236835367 0.15937611236835367 0.15937611236835367 0.15937611236835367 0.15937611236835367 0.22604277903502035 0.22604277903502035 0.22604277903502035 0.22604277903502035 0.22604277903502035 0.22604277903502035 0.22604277903502035 0.22604277903502035 0.22604277903502035 0.22604277903502035 0.22604277903502035 0.22604277903502035 0.292709445701687 0.292709445701687 0.292709445701687 0.292709445701687 0.292709445701687 0.292709445701687 0.292709445701687 0.292709445701687 0.292709445701687 0.292709445701687 0.292709445701687 0.292709445701687 0.35937611236835365 0.35937611236835365 0.35937611236835365 0.35937611236835365 0.35937611236835365 0.35937611236835365 0.35937611236835365 0.35937611236835365 0.35937611236835365 0.35937611236835365 0.35937611236835365 0.35937611236835365 0.4260427790350203 0.4260427790350203 0.4260427790350203 0.4260427790350203 0.4260427790350203 0.4260427790350203 0.4260427790350203 0.4260427790350203 0.4260427790350203 0.4260427790350203 0.4260427790350203 0.4260427790350203 0.492709445701687 0.492709445701687 0.492709445701687 0.492709445701687 0.492709445701687 0.492709445701687 0.492709445701687 0.492709445701687 0.492709445701687 0.492709445701687 0.492709445701687 0.492709445701687 0.5593761123683537 0.5593761123683537 0.5593761123683537 0.5593761123683537 0.5593761123683537 0.5593761123683537 0.5593761123683537 0.5593761123683537 0.5593761123683537 0.5593761123683537 0.5593761123683537 0.5593761123683537 0.6260427790350204 0.6260427790350204 0.6260427790350204 0.6260427790350204 0.6260427790350204 0.6260427790350204 0.6260427790350204 0.6260427790350204 0.6260427790350204 0.6260427790350204 0.6260427790350204 0.6260427790350204 0.692709445701687 0.692709445701687 0.692709445701687 0.692709445701687 0.692709445701687 0.692709445701687 0.692709445701687 0.692709445701687 0.692709445701687 0.692709445701687 0.692709445701687 0.692709445701687 0.7593761123683537 0.7593761123683537 0.7593761123683537 0.7593761123683537 0.7593761123683537 0.7593761123683537 0.7593761123683537 0.7593761123683537 0.7593761123683537 0.7593761123683537 0.7593761123683537 0.7593761123683537 0.8260427790350203 0.8260427790350203 0.8260427790350203 0.8260427790350203 0.8260427790350203 0.8260427790350203 0.8260427790350203 0.8260427790350203 0.8260427790350203 0.8260427790350203 0.8260427790350203 0.8260427790350203 0.8927094457016871 0.8927094457016871 0.8927094457016871 0.8927094457016871 0.8927094457016871 0.8927094457016871 0.8927094457016871 0.8927094457016871 0.8927094457016871 0.8927094457016871 0.8927094457016871 0.8927094457016871 0.9593761123683537 0.9593761123683537 0.9593761123683537 0.9593761123683537 0.9593761123683537 0.9593761123683537 0.9593761123683537 0.9593761123683537 0.9593761123683537 0.9593761123683537 0.9593761123683537 0.9593761123683537 1.0260427790350204 1.0260427790350204 1.0260427790350204 1.0260427790350204 1.0260427790350204 1.0260427790350204 1.0260427790350204 1.0260427790350204 1.0260427790350204 1.0260427790350204 1.0260427790350204 1.0260427790350204 1.092709445701687 1.092709445701687 1.092709445701687 1.092709445701687 1.092709445701687 1.092709445701687 1.092709445701687 1.092709445701687 1.092709445701687 1.092709445701687 1.092709445701687 1.092709445701687 0.185418891403374 0.185418891403374 0.185418891403374 0.185418891403374 0.185418891403374 0.185418891403374 0.185418891403374 0.185418891403374 0.185418891403374 0.185418891403374 0.185418891403374 0.185418891403374 0.2520855580700407 0.2520855580700407 0.2520855580700407 0.2520855580700407 0.2520855580700407 0.2520855580700407 0.2520855580700407 0.2520855580700407 0.2520855580700407 0.2520855580700407 0.2520855580700407 0.2520855580700407 0.31875222473670733 0.31875222473670733 0.31875222473670733 0.31875222473670733 0.31875222473670733 0.31875222473670733 0.31875222473670733 0.31875222473670733 0.31875222473670733 0.31875222473670733 0.31875222473670733 0.31875222473670733 0.38541889140337404 0.38541889140337404 0.38541889140337404 0.38541889140337404 0.38541889140337404 0.38541889140337404 0.38541889140337404 0.38541889140337404 0.38541889140337404 0.38541889140337404 0.38541889140337404 0.38541889140337404 0.4520855580700407 0.4520855580700407 0.4520855580700407 0.4520855580700407 0.4520855580700407 0.4520855580700407 0.4520855580700407 0.4520855580700407 0.4520855580700407 0.4520855580700407 0.4520855580700407 0.4520855580700407 0.5187522247367073 0.5187522247367073 0.5187522247367073 0.5187522247367073 0.5187522247367073 0.5187522247367073 0.5187522247367073 0.5187522247367073 0.5187522247367073 0.5187522247367073 0.5187522247367073 0.5187522247367073 0.585418891403374 0.585418891403374 0.585418891403374 0.585418891403374 0.585418891403374 0.585418891403374 0.585418891403374 0.585418891403374 0.585418891403374 0.585418891403374 0.585418891403374 0.585418891403374 0.6520855580700406 0.6520855580700406 0.6520855580700406 0.6520855580700406 0.6520855580700406 0.6520855580700406 0.6520855580700406 0.6520855580700406 0.6520855580700406 0.6520855580700406 0.6520855580700406 0.6520855580700406 0.7187522247367073 0.7187522247367073 0.7187522247367073 0.7187522247367073 0.7187522247367073 0.7187522247367073 0.7187522247367073 0.7187522247367073 0.7187522247367073 0.7187522247367073 0.7187522247367073 0.7187522247367073 0.785418891403374 0.785418891403374 0.785418891403374 0.785418891403374 0.785418891403374 0.785418891403374 0.785418891403374 0.785418891403374 0.785418891403374 0.785418891403374 0.785418891403374 0.785418891403374 0.8520855580700406 0.8520855580700406 0.8520855580700406 0.8520855580700406 0.8520855580700406 0.8520855580700406 0.8520855580700406 0.8520855580700406 0.8520855580700406 0.8520855580700406 0.8520855580700406 0.8520855580700406 0.9187522247367073 0.9187522247367073 0.9187522247367073 0.9187522247367073 0.9187522247367073 0.9187522247367073 0.9187522247367073 0.9187522247367073 0.9187522247367073 0.9187522247367073 0.9187522247367073 0.9187522247367073 0.985418891403374 0.985418891403374 0.985418891403374 0.985418891403374 0.985418891403374 0.985418891403374 0.985418891403374 0.985418891403374 0.985418891403374 0.985418891403374 0.985418891403374 0.985418891403374 1.0520855580700408 1.0520855580700408 1.0520855580700408 1.0520855580700408 1.0520855580700408 1.0520855580700408 1.0520855580700408 1.0520855580700408 1.0520855580700408 1.0520855580700408 1.0520855580700408 1.0520855580700408 1.1187522247367074 1.1187522247367074 1.1187522247367074 1.1187522247367074 1.1187522247367074 1.1187522247367074 1.1187522247367074 1.1187522247367074 1.1187522247367074 1.1187522247367074 1.1187522247367074 1.1187522247367074 1.185418891403374 1.185418891403374 1.185418891403374 1.185418891403374 1.185418891403374 1.185418891403374 1.185418891403374 1.185418891403374 1.185418891403374 1.185418891403374 1.185418891403374 1.185418891403374 0.278128337105061 0.278128337105061 0.278128337105061 0.278128337105061 0.278128337105061 0.278128337105061 0.278128337105061 0.278128337105061 0.278128337105061 0.278128337105061 0.278128337105061 0.278128337105061 0.34479500377172767 0.34479500377172767 0.34479500377172767 0.34479500377172767 0.34479500377172767 0.34479500377172767 0.34479500377172767 0.34479500377172767 0.34479500377172767 0.34479500377172767 0.34479500377172767 0.34479500377172767 0.4114616704383943 0.4114616704383943 0.4114616704383943 0.4114616704383943 0.4114616704383943 0.4114616704383943 0.4114616704383943 0.4114616704383943 0.4114616704383943 0.4114616704383943 0.4114616704383943 0.4114616704383943 0.47812833710506103 0.47812833710506103 0.47812833710506103 0.47812833710506103 0.47812833710506103 0.47812833710506103 0.47812833710506103 0.47812833710506103 0.47812833710506103 0.47812833710506103 0.47812833710506103 0.47812833710506103 0.5447950037717277 0.5447950037717277 0.5447950037717277 0.5447950037717277 0.5447950037717277 0.5447950037717277 0.5447950037717277 0.5447950037717277 0.5447950037717277 0.5447950037717277 0.5447950037717277 0.5447950037717277 0.6114616704383944 0.6114616704383944 0.6114616704383944 0.6114616704383944 0.6114616704383944 0.6114616704383944 0.6114616704383944 0.6114616704383944 0.6114616704383944 0.6114616704383944 0.6114616704383944 0.6114616704383944 0.678128337105061 0.678128337105061 0.678128337105061 0.678128337105061 0.678128337105061 0.678128337105061 0.678128337105061 0.678128337105061 0.678128337105061 0.678128337105061 0.678128337105061 0.678128337105061 0.7447950037717277 0.7447950037717277 0.7447950037717277 0.7447950037717277 0.7447950037717277 0.7447950037717277 0.7447950037717277 0.7447950037717277 0.7447950037717277 0.7447950037717277 0.7447950037717277 0.7447950037717277 0.8114616704383943 0.8114616704383943 0.8114616704383943 0.8114616704383943 0.8114616704383943 0.8114616704383943 0.8114616704383943 0.8114616704383943 0.8114616704383943 0.8114616704383943 0.8114616704383943 0.8114616704383943 0.878128337105061 0.878128337105061 0.878128337105061 0.878128337105061 0.878128337105061 0.878128337105061 0.878128337105061 0.878128337105061 0.878128337105061 0.878128337105061 0.878128337105061 0.878128337105061 0.9447950037717276 0.9447950037717276 0.9447950037717276 0.9447950037717276 0.9447950037717276 0.9447950037717276 0.9447950037717276 0.9447950037717276 0.9447950037717276 0.9447950037717276 0.9447950037717276 0.9447950037717276 1.0114616704383943 1.0114616704383943 1.0114616704383943 1.0114616704383943 1.0114616704383943 1.0114616704383943 1.0114616704383943 1.0114616704383943 1.0114616704383943 1.0114616704383943 1.0114616704383943 1.0114616704383943 1.0781283371050612 1.0781283371050612 1.0781283371050612 1.0781283371050612 1.0781283371050612 1.0781283371050612 1.0781283371050612 1.0781283371050612 1.0781283371050612 1.0781283371050612 1.0781283371050612 1.0781283371050612 1.1447950037717276 1.1447950037717276 1.1447950037717276 1.1447950037717276 1.1447950037717276 1.1447950037717276 1.1447950037717276 1.1447950037717276 1.1447950037717276 1.1447950037717276 1.1447950037717276 1.1447950037717276 1.2114616704383945 1.2114616704383945 1.2114616704383945 1.2114616704383945 1.2114616704383945 1.2114616704383945 1.2114616704383945 1.2114616704383945 1.2114616704383945 1.2114616704383945 1.2114616704383945 1.2114616704383945 1.278128337105061 1.278128337105061 1.278128337105061 1.278128337105061 1.278128337105061 1.278128337105061 1.278128337105061 1.278128337105061 1.278128337105061 1.278128337105061 1.278128337105061 1.278128337105061]
 
         shape = extrude_geometry((p1, p2, p3); direction, particle_spacing=0.1, n_extrude=4,
-                                 density=1000.0, tlsph=true)
+                                 density=1000.0, place_on_shell=true)
 
         @test shape.coordinates ≈ expected_coords
     end
diff --git a/test/setups/rectangular_shape.jl b/test/setups/rectangular_shape.jl
index f3e77043b..7c2fd6875 100644
--- a/test/setups/rectangular_shape.jl
+++ b/test/setups/rectangular_shape.jl
@@ -41,7 +41,8 @@
             ]
 
             @testset "$(loop_orders[i])" for i in eachindex(loop_orders)
-                shape = RectangularShape(1.0, (2, 2), (0.0, 0.0), density=1.0, tlsph=true,
+                shape = RectangularShape(1.0, (2, 2), (0.0, 0.0), density=1.0,
+                                         place_on_shell=true,
                                          loop_order=loop_orders[i])
 
                 @test shape.coordinates == expected_coords[i]
@@ -242,7 +243,7 @@ end
 
             @testset "$(loop_orders[i])" for i in eachindex(loop_orders)
                 shape = RectangularShape(1.0, (2, 2, 2), (0.0, 0.0, 0.0), density=1.0,
-                                         tlsph=true, loop_order=loop_orders[i])
+                                         place_on_shell=true, loop_order=loop_orders[i])
 
                 @test shape.coordinates == expected_coords[i]
             end
diff --git a/test/setups/sphere_shape.jl b/test/setups/sphere_shape.jl
index 57d904a37..c8b87d76d 100644
--- a/test/setups/sphere_shape.jl
+++ b/test/setups/sphere_shape.jl
@@ -106,14 +106,14 @@
             SphereShape(1.0, 1.1, (0.2, -1.0, 0.3), 1000.0, sphere_type=RoundSphere()),
             SphereShape(1.0, 1.2, (-0.3, 0.1, 0.8), 1000.0, sphere_type=RoundSphere()),
             SphereShape(0.1, 0.5, (0.3, 0.4, 0.5), 1000.0, cutout_min=(0.18, 0.4, 0.5),
-                        cutout_max=(0.42, 10.0, 1.0), tlsph=true),
-            SphereShape(0.1, 0.5, (0.3, 0.4, 0.5), 1000.0, n_layers=2, tlsph=true),
+                        cutout_max=(0.42, 10.0, 1.0), place_on_shell=true),
+            SphereShape(0.1, 0.5, (0.3, 0.4, 0.5), 1000.0, n_layers=2, place_on_shell=true),
             SphereShape(0.1, 0.5, (0.3, 0.4, 0.5), 1000.0, n_layers=2,
-                        layer_outwards=true, tlsph=true),
+                        layer_outwards=true, place_on_shell=true),
             SphereShape(0.1, 0.5, (0.3, 0.4, 0.5), 1000.0, n_layers=2,
                         sphere_type=RoundSphere()),
             SphereShape(0.1, 0.55, (0.3, 0.4, 0.5), 1000.0, n_layers=2, layer_outwards=true,
-                        sphere_type=RoundSphere(), tlsph=true)
+                        sphere_type=RoundSphere(), place_on_shell=true)
         ]
 
         expected_coords = [
diff --git a/test/systems/packing_system.jl b/test/systems/packing_system.jl
index d55afd559..b42e53427 100644
--- a/test/systems/packing_system.jl
+++ b/test/systems/packing_system.jl
@@ -19,7 +19,7 @@
         │ neighborhood search: ………………………… GridNeighborhoodSearch                                           │
         │ #particles: ………………………………………………… 307                                                              │
         │ smoothing kernel: ………………………………… SchoenbergQuinticSplineKernel                                    │
-        │ tlsph: ……………………………………………………………… no                                                               │
+        │ place_on_shell: ……………………………………… no                                                               │
         │ boundary: ……………………………………………………… no                                                               │
         └──────────────────────────────────────────────────────────────────────────────────────────────────┘"""
         @test repr("text/plain", system) == show_box
@@ -36,7 +36,7 @@
         │ neighborhood search: ………………………… GridNeighborhoodSearch                                           │
         │ #particles: ………………………………………………… 307                                                              │
         │ smoothing kernel: ………………………………… SchoenbergQuinticSplineKernel                                    │
-        │ tlsph: ……………………………………………………………… no                                                               │
+        │ place_on_shell: ……………………………………… no                                                               │
         │ boundary: ……………………………………………………… yes                                                              │
         └──────────────────────────────────────────────────────────────────────────────────────────────────┘"""
         @test repr("text/plain", system) == show_box
@@ -52,7 +52,7 @@
         │ neighborhood search: ………………………… Nothing                                                          │
         │ #particles: ………………………………………………… 307                                                              │
         │ smoothing kernel: ………………………………… SchoenbergQuinticSplineKernel                                    │
-        │ tlsph: ……………………………………………………………… no                                                               │
+        │ place_on_shell: ……………………………………… no                                                               │
         │ boundary: ……………………………………………………… no                                                               │
         └──────────────────────────────────────────────────────────────────────────────────────────────────┘"""
     end