diff --git a/.gitignore b/.gitignore
index ef3ee9c..ad995cf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@ _opam/
 _esy/
 
 examples/scads
+examples/pngs/incl_*.png
diff --git a/OSCADml.opam b/OSCADml.opam
index c8ba67e..08711ce 100644
--- a/OSCADml.opam
+++ b/OSCADml.opam
@@ -9,7 +9,7 @@ authors: [
   "Masaki Nakano<namachan10777@gmail.com>"
 ]
 license: "GPL-2.0-or-later"
-tags: ["OCADml" "CAD" "OpenSCAD"]
+tags: ["OCADml" "CAD" "OpenSCAD" "CSG"]
 homepage: "https://github.com/OCADml/OSCADml"
 doc: "https://ocadml.github.io/OSCADml"
 bug-reports: "https://github.com/OCADml/OSCADml/issues"
@@ -18,7 +18,7 @@ depends: [
   "ocaml" {>= "4.14.0"}
   "gg" {>= "1.0.0"}
   "cairo2" {>= "0.6.2"}
-  "OCADml" {>= "0.5.0"}
+  "OCADml" {>= "0.6.0"}
   "odoc" {with-doc}
 ]
 build: [
diff --git a/docs/index.mld b/docs/index.mld
index 0282503..aa29c18 100644
--- a/docs/index.mld
+++ b/docs/index.mld
@@ -85,6 +85,7 @@ should serve as a helpful reference.
 
 {2 Skins and Morphs}
 - {{!page-"profile_skinning"} {b Profile skinning}}
+- {{!page-"spline_skinning"} {b Continuous skinning with Bézier splines}}
 - {{!page-"morphing_sweeps"} {b Morphing sweeps and extrusions}}
 
 {2 Function Plotting}
diff --git a/dune-project b/dune-project
index c17bae2..73aee87 100644
--- a/dune-project
+++ b/dune-project
@@ -27,7 +27,7 @@
  (description
   "OSCADml is an OCaml front-end to the OpenSCAD CAD programming language.")
  (tags
-  ("OCADml" "CAD" "OpenSCAD"))
+  ("OCADml" "CAD" "OpenSCAD" "CSG"))
  (depends
   (ocaml
    (>= 4.14.0))
@@ -36,4 +36,4 @@
   (cairo2
    (>= 0.6.2))
   (OCADml
-   (>= 0.5.0))))
+   (>= 0.6.0))))
diff --git a/examples/arc_points.ml b/examples/arc_points.ml
index bf59f7b..39554e9 100644
--- a/examples/arc_points.ml
+++ b/examples/arc_points.ml
@@ -33,9 +33,7 @@ let () =
   in
   let wedge = Scad.extrude ~height:1. @@ Scad.of_path2 arc
   and marks =
-    Debug.show_path2 show arc
-    |> Scad.translate (v3 0. 0. 1.1)
-    |> Scad.color ~alpha:0.8 Color.Magenta
+    Scad.color ~alpha:0.8 Color.Magenta @@ Scad.ztrans 1.1 (Debug.show_path2 show arc)
   in
   Scad.to_file "arc_wedge_2d.scad" @@ Scad.union [ wedge; marks ]
 
diff --git a/examples/docs/arc_points.mld b/examples/docs/arc_points.mld
index 59cdb5b..2e4414c 100644
--- a/examples/docs/arc_points.mld
+++ b/examples/docs/arc_points.mld
@@ -42,9 +42,7 @@ let () =
   in
   let wedge = Scad.extrude ~height:1. @@ Scad.of_path2 arc
   and marks =
-    Debug.show_path2 show arc
-    |> Scad.translate (v3 0. 0. 1.1)
-    |> Scad.color ~alpha:0.8 Color.Magenta
+    Scad.color ~alpha:0.8 Color.Magenta @@ Scad.ztrans 1.1 (Debug.show_path2 show arc)
   in
   Scad.to_file "arc_wedge_2d.scad" @@ Scad.union [ wedge; marks ]
 ]}
diff --git a/examples/docs/morphing_sweeps.mld b/examples/docs/morphing_sweeps.mld
index ee4c90d..4e666c2 100644
--- a/examples/docs/morphing_sweeps.mld
+++ b/examples/docs/morphing_sweeps.mld
@@ -18,7 +18,7 @@ let () =
       V3.[ v 0. 0. 2.; v 0. 20. 20.; v 40. 20. 10.; v 30. 0. 10. ]
       |> Path3.quaternion (Quaternion.make (v3 1. 1. 0.) (Float.pi /. -5.))
     in
-    Bezier3.curve ~fn:60 @@ Bezier3.of_path ~size:(`Flat (`Rel 0.3)) control
+    Bezier3.curve ~fn:80 @@ Bezier3.of_path ~size:(`Flat (`Rel 0.3)) control
   and caps =
     Mesh.Cap.(capped ~bot:(round @@ circ (`Radius 0.5)) ~top:(round @@ circ (`Radius 0.5)))
   and a = Poly2.ring ~fn:5 ~thickness:(v2 2.5 2.5) (v2 6. 6.)
diff --git a/examples/docs/polyholes.mld b/examples/docs/polyholes.mld
index 3a75f61..fe635a1 100644
--- a/examples/docs/polyholes.mld
+++ b/examples/docs/polyholes.mld
@@ -23,7 +23,7 @@ let () =
       |> Scad.translate (v3 0. 0. (-3.))
       |> Scad.color ~alpha:0.5 Color.BlueViolet
     in
-    Scad.union [ poly; reference ]
+    Scad.add poly reference
   in
   Scad.to_file "polyholes.scad" scad
 ]}
diff --git a/examples/docs/profile_skinning.mld b/examples/docs/profile_skinning.mld
index 5d6aa67..28f6553 100644
--- a/examples/docs/profile_skinning.mld
+++ b/examples/docs/profile_skinning.mld
@@ -15,14 +15,13 @@ connector.
 
 {[
 let profiles =
-  let fn = 32
-  and up h = Path3.translate (v3 0. 0. h) in
+  let fn = 32 in
   let base =
     let sq = Path3.square ~center:true (v2 2. 4.) in
     Path3.(roundover ~fn (Round.flat ~corner:(Round.circ (`Radius 0.5)) sq))
-  and c r h = up h @@ Path3.circle ~fn r in
+  and c r h = Path3.ztrans h @@ Path3.circle ~fn r in
   let cones = List.map (fun h -> [ c 0.6 h; c 0.5 (h +. 1.) ]) [ 4.; 5.; 6. ] in
-  List.flatten @@ ([ base; up 2. base; c 0.5 3.; c 0.5 4. ] :: cones)
+  List.flatten ([ base; Path3.ztrans 2. base; c 0.5 3.; c 0.5 4. ] :: cones)
 ]}
 
 A quick look at the points of our profiles we are about to mesh over with
@@ -56,15 +55,3 @@ let () =
 <img src="_assets/vaccum_connector.png" style="width:150mm;"/>
 </p> %}
 
-
-{[
-let () =
-  Mesh.skin
-    ~refine:2
-    ~slices:(`Flat 25)
-    ~mapping:(`Flat `Tangent)
-    Path3.[ circle ~fn:5 4.; translate (v3 0. 0. 3.) @@ circle ~fn:80 2. ]
-  |> Scad.of_mesh
-  |> Scad.to_file "tangent_skin_test.scad"
-]}
-
diff --git a/examples/docs/spline.mld b/examples/docs/spline.mld
index 0832a8f..01de021 100644
--- a/examples/docs/spline.mld
+++ b/examples/docs/spline.mld
@@ -10,7 +10,7 @@ Control points that our
 through. 
 
 {[
-let control = [ v2 0. 10.; v2 10. 40.; v2 20. 40.; v2 30. (-20.); v2 40. (-40.) ]
+let control = V2.[ v 0. 10.; v 10. 40.; v 20. 40.; v 30. (-20.); v 40. (-40.) ]
 ]}
 
 Mark our [control] points with the debugging helper
@@ -38,7 +38,7 @@ let line =
 Union our control point [marks] and [line] sweep shapes and output to file. 
 
 {[
-let () = Scad.to_file "spline.scad" (Scad.union [ line; marks ])
+let () = Scad.to_file "spline.scad" (Scad.add line marks)
 ]}
 
 {%html:
diff --git a/examples/docs/spline_skinning.mld b/examples/docs/spline_skinning.mld
new file mode 100644
index 0000000..1e2005b
--- /dev/null
+++ b/examples/docs/spline_skinning.mld
@@ -0,0 +1,96 @@
+{0 Bézier Sklines} 
+
+{[
+open OCADml
+open OSCADml
+]}
+
+{{!OCADml.Mesh.skline} [Mesh.skline]}, like {{!OCADml.Mesh.skin}
+[Mesh.skin]} provides a means of generating a mesh that covers a series of
+given profiles, but where [skin] linearly transistions between each profile
+independently, [skline] splines through each of the paths formed by the
+associated vertices from the first profile to the last (or in a loop).
+to generate meshes that cover over series of profiles. However, unlike
+[skin] only resampling is made available for mapping vertices between
+incomensurate profiles as the point duplication methods (tangent and
+distance) can easily lead to edge intersections. 
+
+{[
+let handle_profiles =
+  let circ = Path3.circle ~fn:64 5. in
+  let base = Path3.scale (v3 1.2 1.2 1.) circ
+  and handle = Path3.scale (v3 0.7 0.7 1.) circ in
+  Path3.
+    [ ztrans (-3.) base
+    ; circ
+    ; translate (v3 15. 0. 20.) (yrot (Float.pi /. 2.) handle)
+    ; xtrans 30. (yrot Float.pi circ)
+    ; translate (v3 30. 0. (-3.)) (yrot Float.pi base)
+    ]
+]}
+
+A quick look at the points of our profiles we are about to spline over with
+alternating colours may help a bit to conceptualize what we are about to
+give {{!OCADml.Mesh.skline} [Mesh.skline]} to work with. 
+
+{[
+let () =
+  let show i =
+    let c = if i mod 2 = 0 then Color.Magenta else Color.Aquamarine in
+    Debug.show_path3 (fun _ -> Scad.(color c @@ sphere 0.2))
+  in
+  List.mapi show handle_profiles |> Scad.union |> Scad.to_file "handle_points.scad"
+]}
+
+{%html:
+<p style="text-align:center;">
+<img src="_assets/handle_points.png" style="width:150mm;"/>
+</p> %}
+
+Using the [?tangents] parameter of {{!OCADml.Bezier3.of_path}
+[Bezier3.of_path]} we can specify the tangents we want for each profile,
+rather than leaving them up to the automatically computed derivatives (that
+may differ for each edge path tracing between the profiles). Here we
+contstrain them to cardinals so we can get a handle that sticks closer to
+right angles. 
+
+{[
+let () =
+  let up = v3 0. 0. 1. in
+  let tangents = `Tangents [ up; up; v3 1. 0. 0.; V3.neg up; V3.neg up ] in
+  Mesh.skline ~fn:200 ~size:(`Flat (`Rel 0.5)) ~tangents handle_profiles
+  |> Scad.of_mesh
+  |> Scad.to_file ~incl:true "handle_skline.scad"
+]}
+
+{%html:
+<p style="text-align:center;">
+<img src="_assets/handle_skline.png" style="width:150mm;"/>
+</p> %}
+
+As mentioned above, continuous curvature loops are also possible. Here we
+morph cyclically through circular and pentagonal profiles by specifying
+[~endcaps:`Loop]. 
+
+{[
+let () =
+  let circ = Path3.circle ~fn:64 5. in
+  let pent = Path3.(circle ~fn:5 5.) in
+  let profs =
+    Path3.
+      [ circ
+      ; translate (v3 15. 0. 20.) (yrot (Float.pi /. 2.) pent)
+      ; xtrans 30. (yrot Float.pi circ)
+      ; translate (v3 15. 0. (-20.)) (yrot (Float.pi *. 1.5) pent)
+      ]
+  in
+  Mesh.skline ~endcaps:`Loop ~fn:200 ~size:(`Flat (`Rel 0.1)) profs
+  |> Scad.of_mesh
+  |> Scad.to_file ~incl:true "edgy_loop.scad"
+]}
+
+{%html:
+<p style="text-align:center;">
+<img src="_assets/edgy_loop.png" style="width:150mm;"/>
+</p> %}
+
diff --git a/examples/dune b/examples/dune
index b03f582..c49dbb3 100644
--- a/examples/dune
+++ b/examples/dune
@@ -15,6 +15,7 @@
   resampled_path
   default_vs_euler_sweeps
   profile_skinning
+  spline_skinning
   morphing_sweeps)
  (libraries OSCADml OCADml.PolyText))
 
diff --git a/examples/morphing_sweeps.ml b/examples/morphing_sweeps.ml
index 73f695d..c834647 100644
--- a/examples/morphing_sweeps.ml
+++ b/examples/morphing_sweeps.ml
@@ -15,7 +15,7 @@ let () =
       V3.[ v 0. 0. 2.; v 0. 20. 20.; v 40. 20. 10.; v 30. 0. 10. ]
       |> Path3.quaternion (Quaternion.make (v3 1. 1. 0.) (Float.pi /. -5.))
     in
-    Bezier3.curve ~fn:60 @@ Bezier3.of_path ~size:(`Flat (`Rel 0.3)) control
+    Bezier3.curve ~fn:80 @@ Bezier3.of_path ~size:(`Flat (`Rel 0.3)) control
   and caps =
     Mesh.Cap.(capped ~bot:(round @@ circ (`Radius 0.5)) ~top:(round @@ circ (`Radius 0.5)))
   and a = Poly2.ring ~fn:5 ~thickness:(v2 2.5 2.5) (v2 6. 6.)
diff --git a/examples/pngs/arc_points_2d.png b/examples/pngs/arc_points_2d.png
index 32bd0e5..4ed2f8d 100644
Binary files a/examples/pngs/arc_points_2d.png and b/examples/pngs/arc_points_2d.png differ
diff --git a/examples/pngs/arc_points_3d.png b/examples/pngs/arc_points_3d.png
index 8cda65d..9cb6d49 100644
Binary files a/examples/pngs/arc_points_3d.png and b/examples/pngs/arc_points_3d.png differ
diff --git a/examples/pngs/arc_wedge_2d.png b/examples/pngs/arc_wedge_2d.png
index c023b48..923e9d3 100644
Binary files a/examples/pngs/arc_wedge_2d.png and b/examples/pngs/arc_wedge_2d.png differ
diff --git a/examples/pngs/bezier_spline_path.png b/examples/pngs/bezier_spline_path.png
index 34ce2e4..32ea760 100644
Binary files a/examples/pngs/bezier_spline_path.png and b/examples/pngs/bezier_spline_path.png differ
diff --git a/examples/pngs/cartesian_gravity_well.png b/examples/pngs/cartesian_gravity_well.png
index 9caa9dd..e9380dc 100644
Binary files a/examples/pngs/cartesian_gravity_well.png and b/examples/pngs/cartesian_gravity_well.png differ
diff --git a/examples/pngs/chamfered_loop.png b/examples/pngs/chamfered_loop.png
index c17c6db..516c9cf 100644
Binary files a/examples/pngs/chamfered_loop.png and b/examples/pngs/chamfered_loop.png differ
diff --git a/examples/pngs/chamfered_square_with_holes.png b/examples/pngs/chamfered_square_with_holes.png
index 5a8f0eb..2670e95 100644
Binary files a/examples/pngs/chamfered_square_with_holes.png and b/examples/pngs/chamfered_square_with_holes.png differ
diff --git a/examples/pngs/circular_rounding.png b/examples/pngs/circular_rounding.png
index 7ed6a5a..20a1b77 100644
Binary files a/examples/pngs/circular_rounding.png and b/examples/pngs/circular_rounding.png differ
diff --git a/examples/pngs/edgy_loop.png b/examples/pngs/edgy_loop.png
new file mode 100644
index 0000000..c4e3d38
Binary files /dev/null and b/examples/pngs/edgy_loop.png differ
diff --git a/examples/pngs/elbow.png b/examples/pngs/elbow.png
index 0fdc6d1..ec4aff5 100644
Binary files a/examples/pngs/elbow.png and b/examples/pngs/elbow.png differ
diff --git a/examples/pngs/handle_points.png b/examples/pngs/handle_points.png
new file mode 100644
index 0000000..6574629
Binary files /dev/null and b/examples/pngs/handle_points.png differ
diff --git a/examples/pngs/handle_skline.png b/examples/pngs/handle_skline.png
new file mode 100644
index 0000000..2135949
Binary files /dev/null and b/examples/pngs/handle_skline.png differ
diff --git a/examples/pngs/helix_extrude.png b/examples/pngs/helix_extrude.png
index a305df5..18ddc80 100644
Binary files a/examples/pngs/helix_extrude.png and b/examples/pngs/helix_extrude.png differ
diff --git a/examples/pngs/helix_path_points.png b/examples/pngs/helix_path_points.png
index 3a2258d..b209e51 100644
Binary files a/examples/pngs/helix_path_points.png and b/examples/pngs/helix_path_points.png differ
diff --git a/examples/pngs/incl_polar_rose.png b/examples/pngs/incl_polar_rose.png
index dda26fd..895dba6 100644
Binary files a/examples/pngs/incl_polar_rose.png and b/examples/pngs/incl_polar_rose.png differ
diff --git a/examples/pngs/offset_poly.png b/examples/pngs/offset_poly.png
index aa8ddfe..ed47efe 100644
Binary files a/examples/pngs/offset_poly.png and b/examples/pngs/offset_poly.png differ
diff --git a/examples/pngs/polar_rose.png b/examples/pngs/polar_rose.png
index dda26fd..895dba6 100644
Binary files a/examples/pngs/polar_rose.png and b/examples/pngs/polar_rose.png differ
diff --git a/examples/pngs/resampled_path.png b/examples/pngs/resampled_path.png
index c889952..9d36bc0 100644
Binary files a/examples/pngs/resampled_path.png and b/examples/pngs/resampled_path.png differ
diff --git a/examples/pngs/rounded_polyhole_sweep.png b/examples/pngs/rounded_polyhole_sweep.png
index 5a023a9..f88666d 100644
Binary files a/examples/pngs/rounded_polyhole_sweep.png and b/examples/pngs/rounded_polyhole_sweep.png differ
diff --git a/examples/pngs/rounded_prism_star.png b/examples/pngs/rounded_prism_star.png
index 76383c4..e6b77bc 100644
Binary files a/examples/pngs/rounded_prism_star.png and b/examples/pngs/rounded_prism_star.png differ
diff --git a/examples/pngs/spiral.png b/examples/pngs/spiral.png
index 30f1699..e26828f 100644
Binary files a/examples/pngs/spiral.png and b/examples/pngs/spiral.png differ
diff --git a/examples/pngs/sweep_path_default.png b/examples/pngs/sweep_path_default.png
index e2e85af..5ff69f2 100644
Binary files a/examples/pngs/sweep_path_default.png and b/examples/pngs/sweep_path_default.png differ
diff --git a/examples/pngs/sweep_path_euler.png b/examples/pngs/sweep_path_euler.png
index 08c550e..9451644 100644
Binary files a/examples/pngs/sweep_path_euler.png and b/examples/pngs/sweep_path_euler.png differ
diff --git a/examples/pngs/sweep_starburst_default.png b/examples/pngs/sweep_starburst_default.png
index dff10a7..03c0fa1 100644
Binary files a/examples/pngs/sweep_starburst_default.png and b/examples/pngs/sweep_starburst_default.png differ
diff --git a/examples/pngs/sweep_starburst_euler.png b/examples/pngs/sweep_starburst_euler.png
index 893f6a1..72261e9 100644
Binary files a/examples/pngs/sweep_starburst_euler.png and b/examples/pngs/sweep_starburst_euler.png differ
diff --git a/examples/pngs/tangent_morph_sweep.png b/examples/pngs/tangent_morph_sweep.png
index 8f4a5c2..df88203 100644
Binary files a/examples/pngs/tangent_morph_sweep.png and b/examples/pngs/tangent_morph_sweep.png differ
diff --git a/examples/pngs/tangent_skin_test.png b/examples/pngs/tangent_skin_test.png
deleted file mode 100644
index f3de799..0000000
Binary files a/examples/pngs/tangent_skin_test.png and /dev/null differ
diff --git a/examples/pngs/test_hull_3d.png b/examples/pngs/test_hull_3d.png
index 1d73681..4977f00 100644
Binary files a/examples/pngs/test_hull_3d.png and b/examples/pngs/test_hull_3d.png differ
diff --git a/examples/polyholes.ml b/examples/polyholes.ml
index 02654d4..5210632 100644
--- a/examples/polyholes.ml
+++ b/examples/polyholes.ml
@@ -22,6 +22,6 @@ let () =
       |> Scad.translate (v3 0. 0. (-3.))
       |> Scad.color ~alpha:0.5 Color.BlueViolet
     in
-    Scad.union [ poly; reference ]
+    Scad.add poly reference
   in
   Scad.to_file "polyholes.scad" scad
diff --git a/examples/profile_skinning.ml b/examples/profile_skinning.ml
index c15088f..2cbaaa4 100644
--- a/examples/profile_skinning.ml
+++ b/examples/profile_skinning.ml
@@ -12,14 +12,13 @@ open OSCADml
     connector. *)
 
 let profiles =
-  let fn = 32
-  and up h = Path3.translate (v3 0. 0. h) in
+  let fn = 32 in
   let base =
     let sq = Path3.square ~center:true (v2 2. 4.) in
     Path3.(roundover ~fn (Round.flat ~corner:(Round.circ (`Radius 0.5)) sq))
-  and c r h = up h @@ Path3.circle ~fn r in
+  and c r h = Path3.ztrans h @@ Path3.circle ~fn r in
   let cones = List.map (fun h -> [ c 0.6 h; c 0.5 (h +. 1.) ]) [ 4.; 5.; 6. ] in
-  List.flatten @@ ([ base; up 2. base; c 0.5 3.; c 0.5 4. ] :: cones)
+  List.flatten ([ base; Path3.ztrans 2. base; c 0.5 3.; c 0.5 4. ] :: cones)
 
 (** A quick look at the points of our profiles we are about to mesh over with
     alternating colours may help a bit to conceptualize what we are about to
@@ -47,12 +46,3 @@ let () =
     <img src="_assets/vaccum_connector.png" style="width:150mm;"/>
     </p> %}
     *)
-
-let () =
-  Mesh.skin
-    ~refine:2
-    ~slices:(`Flat 25)
-    ~mapping:(`Flat `Tangent)
-    Path3.[ circle ~fn:5 4.; translate (v3 0. 0. 3.) @@ circle ~fn:80 2. ]
-  |> Scad.of_mesh
-  |> Scad.to_file "tangent_skin_test.scad"
diff --git a/examples/spline.ml b/examples/spline.ml
index 1e475b3..43e980b 100644
--- a/examples/spline.ml
+++ b/examples/spline.ml
@@ -6,7 +6,7 @@ open OSCADml
 (** Control points that our
     {{:https://mathworld.wolfram.com/CubicSpline.html}cubic spline} will pass
     through. *)
-let control = [ v2 0. 10.; v2 10. 40.; v2 20. 40.; v2 30. (-20.); v2 40. (-40.) ]
+let control = V2.[ v 0. 10.; v 10. 40.; v 20. 40.; v 30. (-20.); v 40. (-40.) ]
 
 (** Mark our [control] points with the debugging helper
     {{!OSCADml.Debug.show_path2} [Debug.show_path2]} for reference. We don't
@@ -25,7 +25,7 @@ let line =
   Scad.of_mesh @@ Mesh.path_extrude ~path rectangle
 
 (** Union our control point [marks] and [line] sweep shapes and output to file. *)
-let () = Scad.to_file "spline.scad" (Scad.union [ line; marks ])
+let () = Scad.to_file "spline.scad" (Scad.add line marks)
 
 (** {%html:
     <p style="text-align:center;">
diff --git a/examples/spline_skinning.ml b/examples/spline_skinning.ml
new file mode 100644
index 0000000..555019b
--- /dev/null
+++ b/examples/spline_skinning.ml
@@ -0,0 +1,87 @@
+(** {0 Bézier Sklines} *)
+
+open OCADml
+open OSCADml
+
+(** {{!OCADml.Mesh.skline} [Mesh.skline]}, like {{!OCADml.Mesh.skin}
+    [Mesh.skin]} provides a means of generating a mesh that covers a series of
+    given profiles, but where [skin] linearly transistions between each profile
+    independently, [skline] splines through each of the paths formed by the
+    associated vertices from the first profile to the last (or in a loop).
+    to generate meshes that cover over series of profiles. However, unlike
+   [skin] only resampling is made available for mapping vertices between
+   incomensurate profiles as the point duplication methods (tangent and
+   distance) can easily lead to edge intersections. *)
+
+let handle_profiles =
+  let circ = Path3.circle ~fn:64 5. in
+  let base = Path3.scale (v3 1.2 1.2 1.) circ
+  and handle = Path3.scale (v3 0.7 0.7 1.) circ in
+  Path3.
+    [ ztrans (-3.) base
+    ; circ
+    ; translate (v3 15. 0. 20.) (yrot (Float.pi /. 2.) handle)
+    ; xtrans 30. (yrot Float.pi circ)
+    ; translate (v3 30. 0. (-3.)) (yrot Float.pi base)
+    ]
+
+(** A quick look at the points of our profiles we are about to spline over with
+    alternating colours may help a bit to conceptualize what we are about to
+    give {{!OCADml.Mesh.skline} [Mesh.skline]} to work with. *)
+let () =
+  let show i =
+    let c = if i mod 2 = 0 then Color.Magenta else Color.Aquamarine in
+    Debug.show_path3 (fun _ -> Scad.(color c @@ sphere 0.2))
+  in
+  List.mapi show handle_profiles |> Scad.union |> Scad.to_file "handle_points.scad"
+
+(** {%html:
+    <p style="text-align:center;">
+    <img src="_assets/handle_points.png" style="width:150mm;"/>
+    </p> %}
+    *)
+
+(** Using the [?tangents] parameter of {{!OCADml.Bezier3.of_path}
+    [Bezier3.of_path]} we can specify the tangents we want for each profile,
+    rather than leaving them up to the automatically computed derivatives (that
+    may differ for each edge path tracing between the profiles). Here we
+    contstrain them to cardinals so we can get a handle that sticks closer to
+    right angles. *)
+
+let () =
+  let up = v3 0. 0. 1. in
+  let tangents = `Tangents [ up; up; v3 1. 0. 0.; V3.neg up; V3.neg up ] in
+  Mesh.skline ~fn:200 ~size:(`Flat (`Rel 0.5)) ~tangents handle_profiles
+  |> Scad.of_mesh
+  |> Scad.to_file ~incl:true "handle_skline.scad"
+
+(** {%html:
+    <p style="text-align:center;">
+    <img src="_assets/handle_skline.png" style="width:150mm;"/>
+    </p> %}
+    *)
+
+(** As mentioned above, continuous curvature loops are also possible. Here we
+    morph cyclically through circular and pentagonal profiles by specifying
+    [~endcaps:`Loop]. *)
+
+let () =
+  let circ = Path3.circle ~fn:64 5. in
+  let pent = Path3.(circle ~fn:5 5.) in
+  let profs =
+    Path3.
+      [ circ
+      ; translate (v3 15. 0. 20.) (yrot (Float.pi /. 2.) pent)
+      ; xtrans 30. (yrot Float.pi circ)
+      ; translate (v3 15. 0. (-20.)) (yrot (Float.pi *. 1.5) pent)
+      ]
+  in
+  Mesh.skline ~endcaps:`Loop ~fn:200 ~size:(`Flat (`Rel 0.1)) profs
+  |> Scad.of_mesh
+  |> Scad.to_file ~incl:true "edgy_loop.scad"
+
+(** {%html:
+    <p style="text-align:center;">
+    <img src="_assets/edgy_loop.png" style="width:150mm;"/>
+    </p> %}
+    *)