Glossary — getting-started-3d-printing

3

3MF: 3D Manufacturing Format — a newer file format that improves on STL by storing units, colour, material, and slicer settings inside one file. Preferred over STL when available; many slicers can save and load 3MF project files that preserve all your settings.

A

ABS: Acrylonitrile Butadiene Styrene — a strong, impact-resistant, and heat-tolerant filament (up to ~100°C). Requires an enclosed printer and 90–110°C bed to prevent warping. Produces fumes during printing — always print in a ventilated space or with an enclosure that filters air. Not recommended as a first filament.

B

Bed adhesion: How well the first layer sticks to the build plate during printing. Good bed adhesion requires a clean surface, correct bed temperature, and properly calibrated Z offset. Poor adhesion causes the print to warp or pop off mid-print.
Bed temperature: The target temperature of the build plate, measured in °C. Typical values: PLA 55–65°C, PETG 70–85°C, ABS 90–110°C. Bed heat keeps the first layer plastic long enough to bond properly and prevents the base of the print from contracting and warping.
Bridge / Bridging: A horizontal span printed over open air, connecting two supported walls. Unlike a straight overhang, a bridge has support on both ends. FDM printers can bridge surprisingly well — up to 80 mm with good cooling — by extruding fast and cooling the plastic quickly mid-air.
Brim: A single-layer flat ring printed around the base of the model, attached to it. A brim increases the footprint contacting the build plate without affecting the model itself, improving adhesion for tall or small-footprint prints. Removed manually after printing.
Build plate / Bed: The flat surface the print adheres to during printing. Usually heated to improve adhesion and reduce warping. Modern printers use a removable spring-steel sheet with PEI coating — flex the sheet to pop off finished prints. Keep it clean with isopropyl alcohol between prints.

E

Elephant's foot: A defect where the bottom of the print flares outward wider than the rest of the model. Caused by the first layer being over-squished (Z offset too low) or the bed temperature being too high, keeping the plastic soft for too long. Fix: raise Z offset in 0.05 mm increments.
Extruder: The motor-driven mechanism that grips and pushes filament toward the hot end at a controlled rate. A 'direct drive' extruder is mounted on the print head directly above the hot end. A 'Bowden' extruder is mounted on the frame and connected to the hot end by a PTFE tube — lighter but with more retraction lag.

F

FDM (Fused Deposition Modeling): The most common desktop 3D printing process. A heated nozzle melts plastic filament and deposits it one layer at a time until a solid object is built up. This is the process used by Prusa, Bambu Lab, Creality, and most other consumer printers.
First layer: The initial layer of a print, deposited directly onto the build plate. The first layer is the most important layer — it must stick well and be evenly squished into the bed surface or the entire print will fail. Always watch the first layer before walking away from a print.

G

G-code: The machine instruction file your printer actually reads. It contains movement commands (G0/G1), temperature settings, fan speeds, and extrusion amounts — one line per action. The slicer generates this from your 3D model; you rarely need to edit it directly.

H

Hot end: The heated assembly at the front of the print head that melts filament. Contains a heater block (heats to print temperature), a thermistor (measures temperature), a heat break (transition between hot and cold zones), and a nozzle. The hot end is one of the most common parts to maintain or replace.

I

Infill: The internal structure printed inside a solid model. Expressed as a percentage: 0% is hollow, 100% is completely solid. Most prints work well at 15% infill for decorative purposes and 40% for functional parts — going higher rarely adds meaningful strength.
Infill pattern: The geometric shape used to fill the interior of a print. Common patterns include grid, gyroid, honeycomb, and rectilinear. For most beginner prints, gyroid or grid at 15% is fine — pattern choice matters more for specialist mechanical applications.

L

Layer height: The thickness of each printed layer, measured in millimetres. A standard layer height for beginners is 0.2 mm — this balances surface quality with print speed. Thinner layers (0.1 mm) produce smoother surfaces but take much longer; thicker layers (0.3 mm) print faster but show more visible lines.
Layer shifting: A defect where one or more layers are suddenly offset horizontally from the layers below, as if the top half of the print was pushed sideways. Caused by loose belts, the nozzle colliding with the print, or print speed too high for the stepper motor to keep up. Fix: check belt tension, lower print speed.

N

Nozzle temperature: The target temperature of the hot end during printing, measured in °C. Typical values: PLA 200–215°C, PETG 230–245°C, ABS 230–250°C. Too low causes under-extrusion; too high causes stringing and burned filament.

O

Overhang: Any section of a model that extends outward without material directly below it. FDM printers can handle overhangs up to roughly 45° from vertical without support. Beyond that, the plastic has nothing to land on and droops or fails.

P

Part cooling fan: A fan on the print head that blows cool air directly onto freshly extruded plastic. Good cooling solidifies each layer quickly, which improves overhangs, bridges, and fine detail. PLA needs strong cooling; ABS needs little or none (too much cooling causes warping and layer delamination).
PEI (spring steel sheet): A spring-steel build plate with a PEI (Polyetherimide) coating. PLA and PETG stick well to PEI when the bed is hot and release cleanly when it cools to room temperature. The best beginner build surface — no glue or hairspray needed for PLA.
PETG: Polyethylene Terephthalate Glycol — a tougher, slightly flexible filament that sits between PLA and ABS in difficulty. Prints at 230–245°C with a 70–85°C bed, no enclosure needed. More resistant to impact and heat than PLA (up to ~80°C). Moisture-sensitive — store sealed with desiccant.
PLA: Polylactic Acid — the most beginner-friendly FDM filament. Prints at 200–215°C with a 60°C bed, requires no enclosure, and sticks well to PEI. Biodegradable under industrial composting conditions. The main weakness: low heat resistance (softens around 60°C), making it unsuitable for hot environments.
Print speed: How fast the print head moves while depositing filament, measured in mm/s. Start at 50 mm/s and only increase after consistent successful prints. Higher speed reduces print time but increases the chance of layer shifts, vibration artefacts, and under-extrusion on sharp corners.

R

Raft: A thick multi-layer platform printed under the entire model, separated from it by a thin gap layer. The raft improves bed adhesion and compensates for an unlevel bed, but adds print time and leaves a rough surface on the bottom of the model.
Retraction: A slicer setting that pulls the filament back a small distance (typically 0.5–2 mm for direct drive, 4–7 mm for Bowden) before a travel move. This reduces ooze from the nozzle and prevents strings from forming between features.

S

Skirt: One or more loops printed around the model before the actual print starts, not touching the model. The skirt primes the nozzle with fresh filament and lets you verify bed leveling and extrusion quality before committing to the model itself.
Slicer: Software that converts a 3D model file (STL or 3MF) into layer-by-layer G-code instructions for the printer. Common slicers include PrusaSlicer and Bambu Studio — both are free.
STL: Standard Triangle Language (or STereoLithography) — the most common 3D model file format for printing. An STL describes only the surface geometry of a shape as a mesh of triangles. It contains no colour, material, or unit information.
Stringing: Thin hairs of plastic that form between features of a print when the nozzle travels over open air and oozes. Caused by too-high nozzle temperature or insufficient retraction. Fix: lower nozzle temperature by 5°C, or increase retraction distance by 0.5 mm increments.
Support: Automatically generated scaffolding printed under overhanging sections of a model that would otherwise sag or fail. Supports are removed after printing. Tree supports (branching structures) are preferred over grid supports — they contact the model at fewer points and leave a cleaner surface.

T

TPU: Thermoplastic Polyurethane — a flexible, rubber-like filament used for cases, gaskets, grips, and anything that needs to bend or compress without breaking. Prints at 220–240°C. Requires a direct-drive extruder for reliable feeding — Bowden setups struggle with flexible filaments. Not a beginner material, but a useful addition once you're comfortable with PLA.

V

Vase mode (spiralize): A slicer mode where the outer wall is printed as a single continuous spiral from bottom to top, with no infill and no top layers. Produces thin-walled decorative objects like vases and lamp shades very quickly. Enable it in PrusaSlicer as 'Spiralize Outer Contour' or in Bambu Studio as 'Vase Mode'.

W

Warping: When the base or corners of a print lift off the build plate during printing. Caused by the outer edges of the print cooling and contracting faster than the interior, creating tension that pulls the base upward. Fix: clean the bed, raise bed temperature, add a brim, or enclose the printer (essential for ABS).

Z

Z-hop: A slicer option that lifts the nozzle slightly (typically 0.2–0.4 mm) before travel moves, then lowers it back down at the destination. Prevents the nozzle from dragging across already-printed features and knocking them loose.