Sculpt something your printer will accept.

Three things, and they are easy to satisfy if you know them in advance and painful to retrofit if you do not. The first is that the mesh must be watertight — one closed surface with no holes, no gaps and no faces that pass through themselves. A slicer works by asking whether a given point is inside or outside the model, and an open mesh makes that question meaningless. This is the single most common cause of a failed print, and a voxel remesh solves it in one operation by rebuilding the sculpt as a continuous shell.

The second is detail scale. Fine work below roughly 0.4 mm at final size will not resolve on a filament printer no matter how good it looks on screen, so pores and fine scratches are wasted effort unless you are printing in resin — which is exactly why tabletop miniatures are resin-printed. Sculpt detail at the size it will actually be seen.

The third is fragility. Thin projections — a sword blade, a whisker, an outstretched finger, an antenna — will snap in your hand even when they print successfully. If something looks delicate on screen it is too delicate in plastic, so thicken it before exporting, however wrong that looks in the render. Overhangs and undercuts need support material or they will fail mid-print.

The workflow that follows is short. Sculpt the form and the detail first and ignore print preparation entirely while you work — it is a finishing step, not a constraint to sculpt under. Then remesh to close the surface, inflate or build up anything thinner than about 2 mm at print scale, decimate if the triangle count is unwieldy, and export STL. Sculpting, remeshing and decimating are all free; downloading the STL is what a paid plan covers, so you can take a model to print-ready before deciding.