The Ultimate FDM 3D Printing Dictionary: Your Complete Guide to FDM Printing Terms

Whether you're just starting your FDM printing journey or looking to expand your knowledge, understanding the terminology is crucial. At Eolas Prints, we believe that knowledge empowers better printing results. This comprehensive dictionary covers everything from basic FDM concepts to the latest 2025 technologies, specifically focused on Fused Deposition Modeling (FDM) printing.

A

ABS (Acrylonitrile Butadiene Styrene) - A strong, durable thermoplastic filament ideal for functional parts. Requires heated bed (80-100°C) and good ventilation. Available at Eolas Prints with ISO 9001 certification.

Acceleration - The rate at which the print head speeds up or slows down during direction changes. Higher acceleration can reduce print time but may cause ringing.

Adaptive Layer Height - Automatically varying layer height based on geometry complexity for optimal quality and speed.

Additive Manufacturing - The technical term for 3D printing, where objects are built layer by layer by adding material.

Adhesion - How well the first layer sticks to the build platform. Poor adhesion leads to warping and print failures.

Annealing - Heat treatment process for PLA to increase strength and temperature resistance.

ASA (Acrylonitrile Styrene Acrylate) - UV-resistant alternative to ABS, perfect for outdoor applications. Available in Eolas Prints' premium filament range.

B

Bed Adhesion Promoter - Materials like Magigoo adhesives that improve first layer bonding to the build platform. Available at Eolas Prints ($20-$88).

Bed Levelling - The process of ensuring the build platform is perfectly level relative to the print nozzle for consistent first layer adhesion.

Bed Temperature - Optimal heated bed settings: PLA (50-60°C), ABS (80-100°C), PETG (70-80°C), TPU (40-50°C), ASA (80-100°C).

Bowden Extruder - A setup where the extruder motor is mounted away from the hot end, connected by a PTFE tube. Reduces moving mass for faster printing.

Bridging - Printing horizontal spans between two points without support material underneath.

Build Envelope/Build Volume - The maximum dimensions of objects that can be printed on a specific 3D printer.

Build Platform/Build Plate - The surface where 3D printed objects are constructed. Often heated to improve adhesion.

C

CAD (Computer-Aided Design) - Software used to create 3D models for printing.

Coasting - A technique that stops filament extrusion slightly before the end of a perimeter to prevent over-extrusion and blobs.

Cold Pull/Atomic Pull - A maintenance technique for cleaning the nozzle by heating, inserting filament, cooling, then pulling it out to remove debris.

Cooling Fan - Fan that cools the printed plastic immediately after extrusion to improve surface quality and prevent drooping.

Crystallization - Process in materials like PETG where molecular structure changes during cooling, affecting transparency.

Cura - Popular open-source slicing software that converts 3D models into printer instructions.

D

Direct Drive Extruder - Configuration where the extruder motor is mounted directly on the print head, providing better control over flexible filaments like TPU.

Drying - Process of removing moisture from hygroscopic filaments like PETG and ABS before printing.

Dual Extrusion - Printing with two different materials or colours simultaneously using two extruders.

E

Elephant Foot - When the bottom layer of a print is slightly wider than intended, usually caused by bed being too hot or nozzle too close.

Extruder - The component that heats and pushes filament through the nozzle to create printed layers.

Extrusion Multiplier - Setting that controls how much filament is pushed through the nozzle.

Extrusion Temperature - The specific temperature at which each filament type melts optimally (PLA: 190-220°C, ABS: 220-260°C, PETG: 220-250°C, TPU: 200-230°C, ASA: 220-260°C).

F

FDM (Fused Deposition Modeling) - The most common 3D printing method where heated filament is extruded through a nozzle layer by layer.

FFF (Fused Filament Fabrication) - Alternative term for FDM, often used to avoid trademark issues.

Filament - The plastic material fed into FDM printers. Eolas Prints offers premium PLA, TPU, PETG, ABS, and ASA filaments manufactured in-house in Cantabria, Spain.

Filament Diameter - Standard sizes are 1.75mm and 3mm, with 1.75mm being most common for desktop FDM printers.

Filament Profiles - Pre-configured settings for specific materials, like the Bambu Lab profiles available for Eolas Prints filaments.

Flow Rate - The amount of filament extruded, typically expressed as a percentage. Adjusting flow rate compensates for filament diameter variations.

Fuzzy Skin - Intentionally rough surface texture created by adding small random movements during perimeter printing.

G

G-Code - The programming language that tells 3D printers how to move and extrude material.

Ghosting/Ringing - Ripple-like artefacts on printed surfaces caused by vibrations during rapid direction changes.

Glass Transition Temperature - The temperature at which a material transitions from rigid to flexible.

H

Heat Break - The component that creates a thermal barrier between the hot end and the heat sink to prevent heat creep.

Heat Creep - When heat travels up the filament path, causing premature softening and potential jams.

Heat Sink - Component that dissipates heat from the hot end to prevent overheating of the extruder mechanism.

Heated Bed - A build platform that maintains elevated temperature to improve adhesion and reduce warping.

Hot End - The heated component of an extruder that melts filament before extrusion.

Hotend Assembly - The complete heating system including heater block, nozzle, thermistor, and heat break.

Hygroscopic - Materials that absorb moisture from air, requiring proper storage and occasional drying. PETG and ABS are hygroscopic.

I

Infill - The internal structure of a 3D printed object. Higher infill percentages create stronger but heavier parts.

Infill Density - Percentage of internal structure fill, typically ranging from 10% (lightweight) to 100% (solid).

Infill Patterns - Different internal structures like honeycomb, grid, gyroid, or cubic that affect strength and material usage.

Ironing - Post-processing technique where the nozzle passes over top surfaces without extruding to create smooth finishes.

J

Jerk - The rate of change of acceleration in 3D printer movement, affecting print quality and speed.

Jerk Settings - Maximum instantaneous speed change the printer can make, affecting print quality and speed.

K

Klipper Firmware - Open-source firmware enabling faster, more precise printing with quicker production cycles.

L

Layer Adhesion - How well each printed layer bonds to the previous one, crucial for part strength.

Layer Height - The thickness of each printed layer. Smaller layer heights create smoother surfaces but increase print time.

Linear Advance - Feature that compensates for pressure buildup in the nozzle during acceleration and deceleration.

M

Melt Zone - The area inside the hot end where solid filament transitions to liquid state.

Mesh - A network of connected triangles that defines the surface of a 3D model.

Monotonic Infill - Infill pattern where lines are printed in consistent directions to improve surface quality on thin walls.

N

Nozzle - The opening through which heated filament is extruded to form printed layers.

Nozzle Diameter - Common sizes include 0.4mm (standard), 0.2mm (fine detail), and 0.8mm (fast printing).

O

Overhang - Parts of a model that extend beyond the layer below, often requiring support material.

Overextrusion - When too much filament is extruded, causing blobs, stringing, and dimensional inaccuracy.

P

Part Cooling - Cooling system specifically for the printed part, separate from hotend cooling.

PETG (Polyethylene Terephthalate Glycol) - A clear, strong filament combining the ease of PLA with the durability of ABS. Bed temperature: 70-80°C. Available in Eolas Prints' premium range.

PLA (Polylactic Acid) - The most beginner-friendly filament, biodegradable and easy to print at low temperatures (190-220°C). Eolas Prints manufactures premium PLA in-house.

Post-Processing - Steps taken after printing to improve surface finish, strength, or appearance.

Pressure Advance - Klipper firmware feature that compensates for pressure changes in the nozzle during printing.

Print Speed - Velocity of the print head during extrusion, typically measured in mm/s. Different speeds for perimeters, infill, and support.

PTFE Tube - Teflon tubing used in Bowden setups to guide filament from extruder to hot end.

Purge Tower - Temporary structure printed to clear the nozzle when changing colors or materials in multi-material printing.

Q

Quality Control - Systematic processes ensuring consistent print quality and material properties. Eolas Prints maintains ISO 9001 and ISO 14001 certifications.

R

Raft - A printed base layer that improves bed adhesion for difficult-to-print objects.

Resolution - The level of detail a 3D printer can achieve, measured in layer height and XY precision.

Retraction - Pulling filament back into the nozzle to prevent stringing during travel moves.

Retraction Distance - How far filament is pulled back into the nozzle to prevent oozing during travel moves.

Retraction Speed - How fast the filament is pulled back during retraction, affecting print quality and speed.

S

Seam Alignment - Control over where layer start/end points are positioned to minimise visible seam lines.

Shore Hardness - Measurement scale for TPU flexibility, with lower numbers indicating softer materials.

Skirt - Outline printed around the object before starting the actual print to prime the nozzle and check bed levelling.

Slicing - Converting a 3D model into layers and generating G-code instructions for printing.

Stepper Motor - Precise motors that control movement of the print head and build platform in exact increments.

Stringing - Thin plastic threads between printed parts, usually caused by poor retraction settings.

Support Material - Temporary structures printed to support overhangs and bridges, removed after printing.

T

Thermistor - Temperature sensor that monitors hot end temperature for precise heating control.

TPU (Thermoplastic Polyurethane) - Flexible filament ideal for phone cases, gaskets, and wearable items. Shore hardness varies by grade. Available in Eolas Prints' flexible filament range.

Travel Move - Non-printing movement of the print head between different areas of the model.

Tree Supports - Organic support structures that use less material and are easier to remove than traditional supports.

U

Underextrusion - Insufficient filament flow resulting in weak, gappy prints.

V

Vase Mode - Printing hollow objects with a single continuous wall, creating lightweight decorative items.

Volumetric Extrusion - Method of controlling filament flow based on volume rather than length, useful for varying filament diameters.

W

Warping - When printed corners lift from the build platform due to cooling stresses.

Wipe Tower - Structure printed to clean the nozzle between material changes in multi-material printing.

X, Y, Z

XYZ Axes - The three-dimensional coordinate system defining printer movement and object positioning.

Z-Hop - Lifting the nozzle slightly during travel moves to avoid hitting previously printed parts.

Z-Offset - Fine adjustment of the nozzle height relative to the bed for optimal first layer adhesion.

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Why Understanding FDM Terms Matters

At Eolas Prints, we know that mastering FDM printing terminology helps you:

1. Optimize Material Selection - Understanding properties of our PLA, TPU, PETG, ABS, and ASA filaments helps you choose the right material for each project
2. Troubleshoot Effectively - Knowing terms like "heat creep," "elephant foot," and "ghosting" helps identify and fix common FDM issues
3. Fine-tune Settings - Understanding concepts like "linear advance," "pressure advance," and "adaptive layer height" helps achieve professional results
4. Communicate with Support - Our technical support team uses these terms to provide precise assistance

Ready to Apply Your FDM Knowledge?

Now that you understand FDM terminology, you're equipped to get the most from your printer. Use our 3D Print Time Calculator to estimate print times with our premium filaments, all manufactured in-house in Cantabria, Spain with ISO 9001 and ISO 14001 certifications.

Need help optimising your FDM settings? Our team provides technical support to help you achieve perfect results with our high-quality materials.