3D Printing Glossary

Plain-English definitions of 3D printing terms. No jargon left unexplained.

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ABS (Acrylonitrile Butadiene Styrene): A common engineering thermoplastic used in FDM 3D printing. Stronger and more heat-resistant than PLA but prone to warping. Requires an enclosed printer and temperatures of 230–260°C. Emits fumes — print in a ventilated space.
AMS (Automatic Material System): Bambu Lab's proprietary multi-filament system. Feeds up to 4 spools into a single print head, enabling multi-color printing. Cuts and splices filament automatically during color changes.
ASA (Acrylonitrile Styrene Acrylate): An engineering filament similar to ABS but with better UV resistance. Ideal for outdoor prints that need to withstand sunlight without yellowing or becoming brittle.
Auto Bed Leveling (ABL): A printer feature that automatically measures the distance from the nozzle to the build surface at multiple points, then compensates in software for an uneven bed. Essential for consistent first layers. Methods include BLTouch, CR Touch, and load-cell probing (Prusa's approach).

Bed Adhesion: How well a print sticks to the build plate during printing. Poor bed adhesion causes prints to detach mid-print. Improved by bed temperature, surface material (PEI is standard), cleaning with isopropyl alcohol, and first-layer height calibration.
Build Volume: The maximum dimensions (X × Y × Z) of an object a printer can produce in a single print. Measured in millimeters. Larger build volumes allow bigger single prints or more objects per batch.

CoreXY: A motion system where both X and Y axes are driven by two fixed motors, with the print head moving in both directions simultaneously. Enables higher speeds than Cartesian (bedslinger) designs because the print head is lighter. Used in Bambu Lab and Creality K1 printers.

DLP (Digital Light Processing): A resin 3D printing technology that uses a digital projector to cure an entire layer at once. Competes with MSLA. DLP uses a UV projector; MSLA uses an LCD mask. Both cure one full layer per exposure regardless of layer size.

FDM (Fused Deposition Modeling): The most common type of 3D printing. Melts thermoplastic filament and deposits it layer by layer. Accessible, safe, and versatile — handles PLA, PETG, ABS, TPU, and more. Also called FFF (Fused Filament Fabrication).

Input Shaping: A firmware algorithm that measures and compensates for printer vibration at high speeds. Without it, fast printing causes 'ghosting' or 'ringing' — wavy artifacts on print surfaces. With input shaping, printers like the Bambu Lab A1 reach 500 mm/s while maintaining clean surfaces.

Klipper: An open-source 3D printer firmware that offloads computation to a separate computer (Raspberry Pi or similar). More powerful than Marlin, enables input shaping, pressure advance, and remote control via a web interface. Standard on Elegoo Neptune and many Creality printers.

Layer Height: The thickness of each printed layer, measured in mm. Common values: 0.1mm (fine detail), 0.2mm (standard), 0.3mm (fast/draft). Smaller layer heights produce smoother surfaces and better detail but take longer. Larger layer heights print faster with slightly visible layer lines.

MSLA (Masked Stereolithography Apparatus): The dominant resin 3D printing technology. Uses an LCD screen to selectively block UV light, curing one full layer at a time. Monochrome LCDs (mono LCD) are faster and more durable than older color LCD panels. All mainstream resin printers (Elegoo, Anycubic, Phrozen) use MSLA.

Nozzle: The metal tip at the end of the print head through which melted filament is extruded. Standard diameter: 0.4mm. Smaller nozzles (0.2mm) produce finer detail. Larger nozzles (0.6–1.0mm) print faster. Brass nozzles work for standard filaments; hardened steel nozzles are required for abrasive filaments (carbon fiber, glow-in-the-dark).

PETG (Polyethylene Terephthalate Glycol): A popular filament that combines the ease of PLA with better strength and temperature resistance. Slightly flexible, good layer adhesion, and moisture resistant. The go-to filament for functional parts that need more durability than PLA.
PLA (Polylactic Acid): The most beginner-friendly filament. Derived from plant starch, easy to print (180–220°C, no heated enclosure needed), available in hundreds of colors. Biodegradable but brittle and softens at ~60°C — not suitable for high-temperature applications.
PEI (Polyetherimide): A spring-steel build plate surface coated with PEI that provides excellent adhesion when hot and easy release when cool. The current standard for FDM printers. Most modern printers include a PEI magnetic spring-steel plate.
Pressure Advance (PA): A firmware feature that compensates for filament pressure buildup in the hotend. Without it, corners and sharp features 'blob' as excess pressure releases. With PA calibrated, corners are crisp and extrusion is consistent at speed.

Resin: Liquid photopolymer used in MSLA and DLP printers. Cures (hardens) under UV light. Produces far finer detail than FDM but requires handling precautions (gloves, ventilation), post-processing (washing and UV curing), and proper disposal. Cannot be poured down drains.

Slicer: Software that converts a 3D model file (STL, 3MF, OBJ) into instructions the printer can follow (G-code). Controls layer height, print speed, support structures, infill, and more. Major slicers: Bambu Studio, PrusaSlicer, Ultimaker Cura.
Support Structures: Temporary scaffolding printed alongside the model to support overhanging sections that would otherwise print in mid-air. Removed after printing. Modern slicers generate supports automatically; placement and density are configurable.

TPU (Thermoplastic Polyurethane): A flexible filament used for printing rubber-like parts: phone cases, gaskets, shoe insoles, flexible hinges. Requires a direct-drive extruder for reliable printing (Bowden extruders struggle with flexible filaments).

XY Resolution: In resin printing, the size of the smallest detail the LCD screen can resolve in the horizontal plane. Measured in microns (µm). Lower is better — 19 µm means each "pixel" is 0.019 mm wide. Determines the fineness of detail on miniatures and jewelry.