Reference
3D Printing Glossary
Every term you need to know, explained clearly. 71 definitions.
FDM
Fused Deposition Modeling. The most common 3D printing technology. A heated nozzle melts thermoplastic filament and deposits it layer by layer.
MSLA
Masked Stereolithography. A resin printing technology that uses an LCD screen to mask UV light, curing an entire layer at once.
SLA
Stereolithography. The original 3D printing technology. Uses a UV laser to cure liquid resin layer by layer.
PLA
Polylactic Acid. The most popular 3D printing filament. Biodegradable, easy to print, excellent detail quality. Low heat resistance (~60C).
PETG
Polyethylene Terephthalate Glycol. A popular engineering filament. Stronger and more heat-resistant than PLA. Slightly flexible.
ABS
Acrylonitrile Butadiene Styrene. A strong, heat-resistant engineering plastic. Requires an enclosure to prevent warping.
ASA
Acrylonitrile Styrene Acrylate. Similar to ABS but with better UV resistance. Excellent for outdoor parts.
TPU
Thermoplastic Polyurethane. A flexible filament. Used for phone cases, gaskets, and flexible parts.
Nylon (PA)
Polyamide. A strong, flexible engineering material with excellent impact resistance. Extremely hygroscopic.
AMS
Automatic Material System. Bambu Lab multi-filament system for automatic material switching.
Input Shaper
A firmware feature that measures and compensates for printer resonance frequencies, allowing higher print speeds.
Bed Leveling
The process of ensuring the print bed is perfectly level relative to the nozzle. Modern printers use automatic mesh bed leveling.
Z-Offset
The distance between the nozzle and the bed at the start of a print. Too high = poor adhesion. Too low = nozzle scrapes bed.
Retraction
A slicer setting that pulls filament back into the nozzle when traveling between print areas to prevent stringing.
Stringing
Thin strings of filament left between parts of a print during travel moves. Caused by incorrect retraction settings or wet filament.
Layer Height
The thickness of each printed layer. Smaller = more detail, longer print time. Larger = faster print, less detail.
Infill
The internal structure of a 3D print. Expressed as a percentage. Higher infill = stronger part, more filament, longer print time.
Supports
Temporary structures printed to support overhanging features. Removed after printing.
PEI
Polyetherimide. A popular print surface material. Excellent adhesion when warm, releases prints easily when cool.
CoreXY
A printer motion system where two motors work together to move the print head in X and Y. Faster than Cartesian systems at high speeds.
Direct Drive
An extruder configuration where the motor is mounted directly on the print head. Better for flexible filaments.
Bowden
An extruder configuration where the motor is mounted on the frame and filament is fed through a tube to the hot end.
Hardened Nozzle
A nozzle made from hardened steel or other wear-resistant materials. Required for abrasive filaments like carbon fiber.
Hygroscopic
A material that absorbs moisture from the air. Wet filament causes poor print quality, stringing, and bubbling.
Slicer
Software that converts a 3D model (STL/3MF) into G-code instructions the printer can execute. Popular options include OrcaSlicer, PrusaSlicer, Cura, and Bambu Studio.
G-code
The instruction language printers read — a list of movement, temperature, and extrusion commands generated by the slicer.
STL
Stereolithography file. The most common 3D model format. Stores surface geometry as triangles but carries no color or units.
3MF
3D Manufacturing Format. A modern model format that stores geometry, color, materials, and print settings in one file.
Brim
A single-layer skirt attached to the base of a print that increases bed contact area to improve adhesion and reduce warping.
Raft
A thick horizontal lattice printed beneath the model to improve adhesion on difficult surfaces. Removed after printing.
Skirt
A loop printed around (but not touching) the model to prime the nozzle and confirm bed adhesion before the real print starts.
Warping
When corners or edges of a print lift off the bed as the material cools and contracts. Most common with ABS and ASA.
Elephant's Foot
A bulge at the base of a print caused by the first layers being squished by the weight above and an over-hot bed.
First Layer
The critical initial layer that bonds the print to the bed. Good first-layer calibration is the foundation of a successful print.
Overhang
A section of a print that extends outward beyond the layer below it. Angles past ~45–60° usually need supports.
Bridging
Printing a flat span between two raised points with no support underneath. Relies on fast travel and strong part cooling.
Cooling / Part Cooling Fan
The fan that blows air on the freshly extruded plastic. Critical for PLA and overhangs; reduced or off for ABS/ASA.
Extrusion Multiplier / Flow Rate
A slicer calibration value that scales how much filament is pushed. Tuning it fixes over- and under-extrusion.
Over-extrusion
Too much filament deposited, causing rough surfaces, blobs, and dimensional inaccuracy.
Under-extrusion
Too little filament deposited, causing gaps, weak layers, and thin walls. Often from clogs, wet filament, or low flow.
Layer Adhesion
How well adjacent layers bond. Poor adhesion causes prints to split along layer lines under stress.
Z-banding
Horizontal artifacts repeating up the Z axis, usually from lead-screw or bearing issues.
Ghosting / Ringing
Echo-like ripples after sharp features, caused by printer vibration. Reduced by input shaping and lower acceleration.
Seam
The visible vertical line where each layer starts and stops. Slicers can hide or align it to minimize its appearance.
Purge / Prime
Extruding a small amount of filament before printing (or between color changes) to clear the nozzle and stabilize flow.
Cold Pull / Atomic Pull
A nozzle-cleaning technique where filament is pulled out at a lower temperature to remove debris and clogs.
Heat Creep
When heat travels too far up the hot end and softens filament prematurely, causing jams. Managed by the heat break and cooling.
Hot End
The assembly that melts and extrudes filament — heat break, heater block, thermistor, and nozzle.
Heat Break
The thermal barrier between the hot and cold sections of the hot end that keeps the melt zone sharp and prevents heat creep.
Nozzle Diameter
The size of the nozzle opening (commonly 0.4 mm). Smaller = finer detail; larger = faster prints and stronger parts.
Build Plate / Bed
The surface prints are made on. Common types include PEI (smooth/textured), glass, and spring-steel flex plates.
PEI Sheet
A spring-steel plate coated in PEI. Flexing it pops prints off easily; textured and smooth variants suit different finishes.
Adhesion Aid
Glue stick, hairspray, or purpose-made sprays used to help (or sometimes release) prints on the bed.
Filament Dryer
A heated, ventilated box that drives moisture out of hygroscopic filament to restore print quality.
Spool
The reel filament is wound onto. Typically 1 kg net weight; sold in 1.75 mm (most common) or 2.85 mm diameters.
Purge Block / Prime Tower
A sacrificial structure printed alongside multi-color prints to purge old color from the nozzle at each swap.
Multi-Material / Multi-Color
Printing with more than one filament in a single job, using systems like Bambu's AMS or Prusa's MMU.
Resin Wash & Cure
The mandatory post-processing for resin prints: washing in IPA to remove uncured resin, then curing under UV light.
IPA
Isopropyl Alcohol. Used to wash uncured resin off SLA/MSLA prints. Also handy for cleaning build surfaces.
FEP / nFEP Film
The transparent, non-stick film at the bottom of a resin vat that lets UV light through while releasing each cured layer.
Exposure Time
How long each resin layer is exposed to UV. Too long over-cures (loss of detail); too short causes failed or soft prints.
Supports (Resin)
Thin pillars that hold up overhangs and islands in resin prints, oriented to minimize suction forces and surface marks.
Curing
Hardening photopolymer resin with UV light — during printing and again as a post-process for full strength.
Annealing
Heat-treating a finished print (e.g. PLA, PA-CF) to relieve stress and boost heat resistance and strength — at the cost of slight shrinkage.
Tolerance
The allowable dimensional variation of a part. Tight-fitting assemblies require dialed-in flow and calibration.
Vase Mode / Spiralize
A slicer mode that prints a model as one continuous single-wall spiral with no layer seams — great for decorative vessels.
Ironing
A slicer feature that re-passes the nozzle over top surfaces to smooth them by melting and spreading a thin layer.
Klipper
Open-source printer firmware that offloads motion planning to a Raspberry Pi, enabling input shaping and high speeds.
Marlin
The most widely used open-source 3D-printer firmware, running on the printer's own microcontroller.
Pressure Advance / Linear Advance
A firmware feature that predicts and compensates for pressure in the nozzle, sharpening corners and reducing bulging.
Carbon Fiber (CF) Filament
Base polymers (PLA, PETG, Nylon) reinforced with chopped carbon fiber for stiffness. Abrasive — requires a hardened nozzle.