PrusaSlicer Settings Guide: Key Settings Explained

PrusaSlicer is Prusa Research's free, open-source slicer, developed from Slic3r. It works with any FDM printer, not just Prusa machines. Bambu Studio is based on PrusaSlicer, and OrcaSlicer is a fork of Bambu Studio, which is why the three look so similar. This guide walks through the settings that matter most, in the order you will meet them.

Quick start

1. Install PrusaSlicer and pick your printer in the Configuration Wizard. If it isn't listed, start from a generic FDM profile and set bed size, nozzle diameter and G-code under Printer Settings.
2. Choose a filament and a print profile, then import your model.
3. Slice, scrub through the layer preview, and export G-code or send it to the printer.
4. Change one setting at a time and save the profile when a change works.

Step 1: Installation

Download PrusaSlicer from Prusa's website or from the project's GitHub releases page. It runs on Windows, macOS and Linux. On first launch the Configuration Wizard installs printer, filament and print profiles. Third-party printers are covered by community profiles and by generic profiles you can edit.

Step 2: Simple, Advanced and Expert modes

The mode selector in the top right controls how many settings are visible.

• Simple shows the essentials: layer height, infill, supports and brim.
• Advanced adds more detail such as extrusion widths and cooling.
• Expert shows everything, including per-feature speeds, extrusion multipliers and custom G-code.

Use Expert while you learn where things live. Settings you can't see are still applied; the mode only hides them.

Step 3: Print, Filament and Printer profiles

Configuration is split into three tabs, each saved separately.

• Print Settings: how the model is sliced (layers, walls, infill, speeds, supports).
• Filament Settings: temperatures, cooling, retraction overrides and flow.
• Printer Settings: bed shape, firmware flavor, extruders and start/end G-code.

Edited values show a modified marker until you save them. Use the save icon next to the profile name, otherwise the change is lost when you switch profiles.

Step 4: Layers and perimeters

Layer height sets the detail and speed trade-off. Lower values give finer surfaces and longer prints. As a rule of thumb, keep layer height at or below about 75% of nozzle diameter.

Perimeters is the number of wall loops. Two is a practical minimum; add more for parts under load.

Arachne is the default perimeter generator in current versions. It varies line width so thin walls and tight corners fill properly instead of leaving gaps. Leave it on unless you have a specific reason to use the classic generator.

Seam position options are Aligned, Nearest, Random and Rear. Aligned stacks the seam into one vertical line you can rotate out of sight; Random hides it by scattering it. Recent versions also offer scarf-style seam options; check the Seam section in Expert mode on your installed version.

Spiral vase prints the outer wall as one continuous spiral with no infill or top surface. It suits single-wall vases and one object per print.

Step 5: Infill

Fill density sets how much of the interior is filled. Low values suit display pieces; higher values suit parts that carry load.

Fill pattern: Gyroid gives fairly even strength in all directions. Grid and Rectilinear print quickly. Cubic and Honeycomb give more 3D strength at a time cost. Lightning is intended for non-structural parts.

Infill anchor controls how far infill extends into the walls. Longer anchors bond infill to the walls better.

Step 6: Skirt and brim

The skirt is a loop printed near the model to prime the nozzle before the part starts. A brim is extra first-layer width attached to the part to resist lifting. Use a brim for tall, narrow or warp-prone parts. Most parts on a clean, level bed don't need one.

Step 7: Filament settings

• Temperatures: start from the profile's values and adjust in small steps for your filament brand.
• Cooling: fan speed and the slow-down-for-layer-time options. Small layers need more time to cool.
• Retraction: direct-drive extruders need much less retraction than Bowden setups. Use the printer profile's value as a starting point.
• Pressure advance: on Prusa firmware this is applied with an M572 command in the filament start G-code (Klipper and Marlin use their own commands). Calibrate it for your printer rather than copying a number.

Step 8: Speeds

PrusaSlicer sets speed per feature type instead of with a single multiplier:

• External perimeters are the visible walls. Slower speeds here improve surface quality.
• Perimeters (inner walls) can run faster because they are hidden.
• Solid infill and top solid infill affect the look of top surfaces; slower is usually better.
• Infill can usually be the fastest category, limited by your hotend's maximum volumetric flow.
• Bridges and first layer have their own speeds. Keep the first layer slow for adhesion.

Raise speeds gradually and watch for under-extrusion, which signals you've hit the hotend's flow limit.

Step 9: Printer settings

Printer Settings holds the bed shape, the firmware flavor, the number of extruders and the start and end G-code. Start G-code is where homing, bed leveling and purge lines live. Edit it carefully and keep a copy of the original.

Step 10: Supports

Support style and support pattern are separate settings.

• Style chooses the structure: Grid, Snug or Organic. Organic (tree-like) supports were added in PrusaSlicer 2.6 and use less material and leave fewer marks on many models.
• Pattern chooses the line pattern inside the support, for example Rectilinear or Honeycomb.
• Overhang threshold sets the angle where support starts.
• Contact Z distance is the gap between the support and the model. A smaller gap gives a cleaner surface but is harder to remove.
• Interface layers add dense layers directly under the model for a cleaner release.

Paint-on supports: use the support painting tool to force supports where you want them (enforcers) or block them (blockers). This is more precise than lowering the global overhang angle.

A raft is a full platform under the model. It helps with warp-prone materials or tiny footprints and is rarely needed otherwise.

Step 11: Variable layer height

Select an object and open the variable layer height tool. You can smooth layer heights across the model or paint finer layers on curved areas and coarser layers on plain walls. This gives detail where it shows and saves time where it doesn't. Check the layer preview afterward to confirm the transitions look right.

Step 12: Z offset and first layer

First-layer height is a printer and firmware feature, not a slider in the slicer. On Prusa printers, use the firmware's live Z adjustment during the first layer, then save the value. Other printers have their own Z-offset setting; set it in firmware or in your start G-code.

Step 13: Multi-material

PrusaSlicer supports multi-material printing with Prusa's MMU units, with other multi-extruder setups, and with manual filament changes. For manual swaps, add a color change at a chosen layer in the layer slider; the slicer inserts a pause so you can change the filament. With several extruders, a wipe tower purges the nozzle between materials. Purge volumes can be tuned per filament pair, and soluble support materials can be assigned as the support interface filament.

Step 14: Other useful features

• Sequential printing (Output options) prints each object completely before the next. The gantry must clear finished objects, so spacing and height limits apply.
• Object list and modifiers let you override settings for one object or region.
• Preview shows speed, flow and feature types by layer, which helps diagnose problems before you print.
• Custom bed textures and shapes can be set in Printer Settings.

Troubleshooting common problems

• First layer won't stick: clean the bed, recheck Z offset, and slow the first layer down.
• Stringing: lower the nozzle temperature a little, check retraction, and dry the filament.
• Gaps in thin walls: make sure Arachne is active and wall widths match the nozzle.
• Poor overhangs: add supports or reduce the overhang by reorienting the part.
• Under-extrusion at high speed: lower speeds or raise the temperature slightly; you may be at the volumetric flow limit.
• Setting changes disappear: save the profile after editing.

Tips

• Change one setting at a time so you can tell what helped.
• Save a known-good profile under a new name before experimenting.
• Use paint-on supports instead of a global overhang change when only one area needs them.
• Inspect the layer preview for every new print.

Version note

This guide was checked against PrusaSlicer 2.9.x. Menu names and defaults change between releases, so if something looks different, check the release notes on the project's GitHub page.