Slicing Basics

A slicer turns your 3D model into G-code — the step-by-step instructions your printer follows. You don't need to learn every setting; a handful of them decide nearly everything about a print.

The settings that actually matter

Layer height. How thick each layer is. 0.2 mm is the everyday default — a good balance of speed and looks. 0.12 mm for visible detail (slower), 0.28 mm for fast drafts. Thinner layers look smoother but every halving roughly doubles print time.

Infill. The interior structure — the slicer doesn't print parts solid. 15–20% infill is plenty for most things; going to 100% rarely makes parts meaningfully stronger and wastes time and plastic. For strength, add walls (perimeters) instead — 3–4 walls beat extra infill for most functional parts.

Supports. Temporary scaffolding for overhangs steeper than about 45°. The slicer generates them; you snap them off after. Orienting the model to minimize overhangs beats printing lots of supports.

Temperatures. Nozzle and bed temperatures come from the filament, not the printer — start with the range printed on the spool (PLA: ~200°C nozzle / 60°C bed) and adjust in 5° steps if you have adhesion or stringing trouble.

Print speed. Defaults are sane. Slow down for detailed or small parts; don't chase the manufacturer's maximum speed until your basic prints are clean.

Brim / raft / skirt. Helpers for bed adhesion. A brim (a flat rim around the part's base) is the useful one — it gives small parts more grip area. A raft (a plastic mat under everything) is rarely needed on a modern printer. A skirt (an outline that doesn't touch the part) just primes the nozzle.

Habits that save filament

Preview before printing. The slicer's layer preview shows supports, infill, and first-layer placement. A 30-second look catches floating models and missing supports.
Change one thing at a time. If a print fails, adjust a single setting and reprint. Changing five things teaches you nothing about which one fixed it.
Keep a note of what works. Filament brand, temperatures, and the profile name that printed well. Future you will thank present you.

Common slicers

OrcaSlicer, PrusaSlicer, Bambu Studio, and Cura are all free and capable. They share the same concepts above — learning one teaches you the vocabulary for all of them. Start with whichever your printer's maker recommends.