Slice Any STL Into Buildable Layers

Stacked or waffle — which build is yours?

Stacked is the solid one: every material-thickness horizontal slice of the model, glued in a pile like a topographic map. Two dowel holes run through every layer — thread two 6 mm rods through and the stack self-aligns; no layer can drift while the glue dries. It uses the most material and the most cutting, and rewards you with a heavy, sandable, paintable solid. This is how life-size figures and terrain models are actually made.

Waffle is the clever one: a handful of vertical ribs along X and another along Y, each slotted where they cross. The slots are half-laps — the X rib slotted from the top to its midpoint, the Y rib from the bottom to its midpoint, each exactly one material-thickness wide — so the grid slides together and locks without a drop of glue. A 3×3 waffle uses a tenth of the material of a full stack and reads beautifully as sculpture, at the cost of being a skeleton rather than a solid.

Both modes respect your material: the thickness you pick sets the layer step in stacked mode and the slot width in waffle mode, so pieces cut at real size fit straight off the machine.

When two slices are the same, stop cutting

Slice a vase, a column, a torso — anything with straight or gently changing sections — and you will find runs of layers whose profiles are identical to within a fraction of a millimetre. Cutting each one from scratch is wasted work: the file, the machine time, sometimes the material itself. Open ♻️ Duplicate layers above the Slice button, set a tolerance, and the slicer finds every run. Each layer in a run is checked against the run's first layer, not its neighbour, so the tolerance can never creep its way down a taper and call a cone a cylinder.

What you do with a run is your call. Cut copies keeps the solid exactly as it was — but where layers 4, 5 and 6 match, you get one file stamped "CUT 3x" and a build list that says which layers it serves. Skip layers goes further: the repeated layers become ghosts — translucent in the assembly preview, absent from the cut list — and dowel spacers bridge each gap. That only makes sense when the stack will be covered with a skin (paper, fibreglass, papier-mâché, fabric), which is precisely how large, light art and decorator pieces are built: the layers give the form and the strength, the skin gives the surface, and every ghosted layer is material and weight you never carry. The stats bar reports the saving in cm³, every piece is printed with its layer thickness, spacer and step, and the settings card button saves a PNG record of the whole job so you can cut the rest of the sheets next weekend.