Glossary

Every term here is also searchable. Each definition is a short version of what its lesson says; follow the link for the full explanation.

3MF

A model file that can carry units, colors, several parts and the full slicer setup, which makes it a good format for saving your own projects. Read more

Bowden

An extruder mounted on the frame that pushes filament through a tube. It lightens the toolhead but adds slack, so it needs more retraction and more pressure advance. Read more

Bridging

Printing a horizontal span between two supported points, like the top of a doorway. Short horizontal bridges can print without support. Read more

Brim

Extra lines attached to the part's first layer that widen its footprint. It helps tall, narrow parts and corners that lift. Read more

Build plate

The surface a print is built on, usually a removable sheet on a heated bed. Most adhesion problems are grease on it. Read more

CoreXY

A motion layout that keeps both XY motors on the frame and moves a light print head, which is why it suits fast printing. Read more

Direct drive

An extruder that sits on the toolhead and pushes filament straight into the hotend, so retraction is crisper and flexible filament feeds more reliably. Read more

DLP

A resin printer that cures each layer with light from a projector. Read more

Elephant's foot

The first layers squashing outward so the base of a print is wider than the walls above. Read more

Exposure time

How long the light stays on to cure each resin layer. Too little and features do not form; too much and they swell. Start from the resin maker's profile. Read more

FDM

Fused deposition modeling: a printer pushes thermoplastic filament through a heated nozzle and draws each layer as a path of melted lines. Also called FFF. Read more

FEP (release film)

The clear, flexible film in the bottom of a resin vat. Light passes through it, and its flexibility lets each layer peel off; replace it if it is scratched, dented or punctured. Read more

FFF

Fused filament fabrication, another name for FDM: filament is melted in a heated nozzle and laid down as thin lines that trace each layer. Read more

First layer

The layer printed directly on the bed. A good one is flat and even, with lines pressed down so they touch their neighbors with no gaps and no ridges. Read more

Flow ratio

A setting that scales how much plastic the slicer asks for; PrusaSlicer calls it the extrusion multiplier. Calibrate it per filament with a test print. Read more

G-code

The finished set of machine instructions a slicer writes for an FDM printer. The printer's firmware turns it into motor steps and heater control. Read more

Hardened nozzle

A hardened steel or other wear-resistant nozzle for abrasive filaments such as carbon fiber and glass fiber fills, which wear brass and stainless nozzles quickly. Read more

Heat break

The part of the hotend that separates the hot and cold sides. Bambu Lab calls it the thermal break. Read more

Heat creep

Heat traveling up from the nozzle into the part of the hotend that should stay cool, so the filament softens too early and jams. It is most common with PLA in a closed enclosure or a hot room. Read more

Hollowing

Printing a resin model with an empty inside to save resin and cut the peel force on each layer. A hollow model needs drainage holes, or uncured resin stays trapped inside. Read more

Hotend

The part that melts filament in a short zone just above the nozzle, while the heat break and a fan-cooled heatsink keep everything above it solid. Read more

Infill

The internal structure an FDM slicer prints inside a part's walls. Its main job is to hold up the top layers. Read more

Input shaping

A firmware feature that uses the printer's measured resonance frequency to reshape each move so the vibration it would start is canceled out, which reduces ringing. Read more

IPA

Isopropyl alcohol, a common solvent for washing resin prints and degreasing some build sheets. Never use it to clean resin off skin; use soap and water. Read more

Klipper

Printer firmware that splits the work between a host computer and the printer's board and reads a text config file. Read more

Layer height

How thick each printed layer is. Thinner layers show less stair-stepping on slopes and curves but take proportionally longer to print. Read more

Line width

How wide each extruded line is. Nozzle diameter sets the line widths a printer can use, and the slicer is told what width to print. Read more

Marlin

Printer firmware that runs entirely on the printer's mainboard and is configured at build time. Read more

Mesh bed leveling

Probing the bed at a grid of points, then moving Z during the print to follow that measured shape. A mesh does not fix a wrong Z offset, a skewed frame or a bad probe. Read more

MSLA

Masked stereolithography, also called an LCD printer: LEDs shine up through an LCD screen that masks each layer's shape. Most hobby resin printers work this way. Read more

Nozzle

The tip that shapes the extruded line. Smaller nozzles are more detailed, slower and more clog-prone; larger ones flow more plastic and resist clogs. Read more

Overhang

Any surface that leans outward over empty space. Past a certain angle it needs support, a new orientation or a redesign. Read more

PEI

A common build sheet surface. Smooth PEI grips most filaments strongly but can bond too well to PETG and TPU, which need a thin glue stick layer as a release. Read more

Perimeter (wall)

The outlines printed around every layer. Walls carry most of a part's strength, so add walls before adding infill. Read more

PETG

A tougher, more heat-resistant step up from PLA with low warping. Expect more stringing, weaker overhangs and very strong grip on smooth PEI. Read more

PLA

The easiest common filament: low warping, good detail and no enclosure needed. It is brittle and softens at around 60 °C. Read more

Post-cure

Curing a washed and fully dried resin print with UV light, using the resin maker's cure times. Read more

Pressure advance

Pushing extra filament as the head speeds up and easing off as it slows, so corners do not bulge and line starts are not thin. Marlin calls its version Linear Advance. Read more

Raft

A whole platform printed under the part. Use it last, because it costs time and material and leaves a rougher bottom. Read more

Retraction

Pulling filament back before a travel move so the nozzle does not ooze across the gap. Too little leaves strings; too much risks under-extrusion, grinding and clogs. Read more

SDS

Safety data sheet: the material maker's document that sets the gloves, eye protection, ventilation and disposal it needs. Read your resin's SDS before you open the bottle. Read more

Skirt

A loop printed around the part that primes the nozzle. It adds no adhesion. Read more

SLA

Stereolithography: a resin printer that cures each layer of liquid resin with a laser. Read more

Slicer

The program that turns a 3D model into printer instructions. Layers, infill, supports and temperatures are set here, not in the model. Read more

STL

A file that describes a model's shape as triangles. It carries no units, colors or settings. Read more

Stringing

Fine hairs or webs between parts of a print, left by molten plastic oozing from the nozzle while it travels. Read more

Support

Structure printed under any part of a model that hangs out too far to rest on the layer below. Supports leave marks where they touch. Read more

Top and bottom layers

The solid skins that close a part over its infill. Think in thickness, not count, because the same number of layers is thinner at a fine layer height. Read more

TPU

A flexible, tough filament that barely warps. Print it slowly, with gentle retraction and dry filament. Read more

Tramming

Turning the screws or knobs under the bed until the bed is parallel to the nozzle's path. It is a mechanical adjustment, not a software one. Read more

Tree support

A support type suited to complex models with small, curved overhangs, where it uses less material and time. Normal supports usually give a better surface under large flat overhangs. Read more

Vat

The resin tank on a resin printer. The build platform lowers into it, and cured flakes left inside can press into the film and screen. Read more

Volumetric flow

How many cubic millimeters of plastic per second the hotend is asked to melt. Print speed is capped by the hotend's volumetric flow limit. Read more

Warping

A part shrinking as it cools and pulling its own corners up off the plate. Read more

Z offset

The distance between the nozzle and the bed when the printer thinks it is at zero. Too high and lines do not stick; too low and plastic cannot flow out. Read more