Slicer Settings That Actually Matter (Cura, PrusaSlicer, Bambu, Orca)

Every slicer exposes several hundred settings, and about a dozen of them account for nearly all the difference between a good print and a bad one. Worse, the same setting has a different name in each program, which makes advice from one community hard to apply in another. Here is the short list, what each one does, and what it’s called where.

The Translation Table

Once you know the mapping, a settings recommendation written for any of them is usable in all of them.

Layer Height

The single biggest lever on print time and surface quality. Halving it roughly doubles the print.

• 0.28-0.32mm - draft. Fast, visibly stepped, structurally fine.
• 0.2mm - the standard. Good balance for almost everything.
• 0.12-0.16mm - fine detail. Miniatures, smooth curves, visible parts.
• 0.08mm and below - rarely worth it on FDM. You hit the limits of everything else first.

Keep layer height under about 75% of the nozzle diameter. A 0.4mm nozzle tops out around 0.3mm layers; past that, layers don’t bond reliably.

Layer height does not meaningfully change strength in the way people expect. Thinner layers mean more layer boundaries, which is the weak axis, so very fine layers can actually be slightly weaker in the Z direction.

Walls and Perimeters

Walls do most of the structural work in a printed part, which makes this the most under-used setting on the list.

• 2 walls - the default, fine for decorative work.
• 3 walls - the right default for anything functional.
• 4-5 walls - parts under real load, or parts you’ll tap threads into.

Adding a perimeter is nearly always a better use of filament than raising infill. If your part broke, start here.

Top and Bottom Layers

Solid faces on the outside of the part. Too few and you get “pillowing”, where the top surface sags between infill lines and leaves visible gaps.

The rule is thickness, not count: aim for at least 0.8mm of solid material, so four layers at 0.2mm or six at 0.12mm. For a flat part that flexes, more top and bottom layers stiffen it far more than infill does.

Infill

Density and pattern are one decision. Most parts want 15-20% with gyroid or grid; functional parts want 25-40%; almost nothing wants more than 60%. The pattern determines which directions the part is strong in.

Temperature

Start in the middle of the range printed on the spool, then move in 5C steps: up for weak layers and under-extrusion, down for stringing and lost detail. First layer gets +5C and no fan.

Speed

Modern slicers break speed into a dozen categories, and they are not equally important.

• Outer wall speed matters most for surface quality. Slowing it to 25-40 mm/s improves the visible finish more than any other single change.
• Infill speed can be fast; nobody sees it.
• First layer speed should be 20-25 mm/s regardless of the rest of the profile.
• Travel speed should be as fast as the machine allows, since it reduces oozing.

Raising overall speed raises the volumetric flow the hotend must sustain, so a fast profile usually needs 15-25C more nozzle temperature than a slow one. That’s why copying speed numbers without the temperature that went with them causes under-extrusion.

Retraction

Pulls filament back on travel moves so the nozzle doesn’t ooze. The right number depends entirely on the extruder type, and this is the setting most often copied from the wrong machine.

• Direct drive - 0.5-2mm at 25-45 mm/s.
• Bowden - 4-7mm at 25-45 mm/s.

Too little retraction leaves strings. Too much pulls molten plastic up into the cold zone, which causes clogs and heat creep. If you’re fighting stringing, dry the filament and lower the temperature before you push retraction past these ranges.

Cooling

• PLA - 100%.
• PETG - 30-50%. Full cooling splits PETG layers.
• ABS and ASA - 0-20%, plus an enclosure.
• TPU - 30-60%.

Every material wants the fan off for the first layer or two.

Supports

Overhangs steeper than about 45 degrees from vertical need support, though a well-tuned machine will bridge further than people expect.

• Support type: tree supports use less material and mark the surface less on organic shapes; normal supports are more reliable on flat overhangs and boxy parts.
• Z distance: the gap between support and part. Roughly half a layer height for easy removal. Too small and it welds on; too large and the surface above it droops.
• Support on build plate only avoids the worst surface damage by refusing to support anything mid-part.

Before adding support, try rotating the model. A part reoriented to eliminate overhangs prints faster, looks better, and is usually stronger.

Bed Adhesion

• Skirt - a loose outline that primes the nozzle. Use it always; it costs nothing.
• Brim - a flat collar attached to the part. The right answer for small footprints, tall parts, and warp-prone materials.
• Raft - a full platform under the part. Rarely needed on a machine with a working first layer, and it wastes filament and time.

Setting Up a Profile in Ten Minutes

1. Start from the built-in profile for your printer and nozzle size. Don’t start from scratch.
2. Set the nozzle and bed temperature from the spool label.
3. Set walls to 3 and top/bottom to 0.8mm of thickness.
4. Set infill to 20% gyroid.
5. Set retraction to the right range for your extruder type.
6. Print a calibration cube and a temperature tower before you print anything you care about.
7. Save it as a named profile, per material, not per project.

Change One Thing at a Time

The reason settings advice is so contradictory online is that most of it was arrived at by changing three things and reporting the one the author believed in. Change a single value, reprint the same test object, and write down what happened.

That log is the actual asset. Gyroid keeps settings, material, printer, and result together on every logged print, so “what did I do the last time this worked” is a search rather than an archaeology project.