3D Printer Filament Types: A Beginner's Guide to PLA, PETG, ABS, and Beyond

The Filament Landscape

Walk into a filament aisle or browse an online store and you'll see dozens of materials, blends, and colours. Most of them you don't need. The reality is that 90% of prints use one of four materials: PLA, PETG, ABS (or ASA), or TPU. Understand those and you can handle almost anything.

PLA: The Default Choice

What it is: Polylactic acid, a bioplastic derived from corn starch or sugarcane. The most common filament by far.

Why it's popular: Easy to print. Low warping. No enclosure needed. Good detail. Cheap. Smells slightly sweet when printing.

Temperature: 190-220°C nozzle, 50-60°C bed (or unheated with tape).

When to use it: Display models, prototypes, decorative items, anything that won't be exposed to heat or mechanical stress.

Limitations: Brittle. Low heat resistance (starts softening around 50°C). Not suitable for outdoor use (UV degrades it). Not strong enough for load-bearing parts.

Variants: PLA+ (tougher, slightly more heat resistant), Silk PLA (metallic sheen), Matte PLA (non-reflective finish), PLA-CF (carbon fibre filled for rigidity).

PETG: The Workhorse

What it is: Polyethylene terephthalate glycol — essentially the same plastic as water bottles, modified for 3D printing.

Why it's popular: Stronger than PLA, easier to print than ABS. Good chemical resistance. Slightly flexible (doesn't shatter like PLA). Still doesn't require an enclosure.

Temperature: 230-250°C nozzle, 70-80°C bed.

When to use it: Functional parts, mechanical components, outdoor items, anything that needs more durability than PLA.

Limitations: Stringy. Poor overhang performance. Sticks aggressively to beds (needs a release agent on PEI). Not as heat resistant as ABS/ASA.

Variants: PETG-CF (carbon fibre, reduced stringing, stiffer), PETG-GF (glass fibre, similar benefits).

ABS and ASA: Engineering Materials

What they are: Petroleum-based thermoplastics. ABS is the classic; ASA is UV-stable ABS for outdoor use.

Why they're used: High temperature resistance (softening point around 100°C). Strong and impact-resistant. Can be smoothed with acetone vapour. ASA is weather-resistant for outdoor applications.

Temperature: 230-260°C nozzle, 90-110°C bed.

Requirements: Enclosure absolutely necessary. Draft-free environment. Good ventilation (ABS emits styrene, which isn't great to breathe).

When to use it: Automotive parts, functional components exposed to heat, outdoor items (ASA specifically), parts that need post-processing (acetone smoothing).

Limitations: Warps aggressively. Needs high bed temperatures. Enclosure required. ABS degrades in sunlight; use ASA instead for outdoor applications. Ventilation matters for health.

TPU: Flexible Filament

What it is: Thermoplastic polyurethane — a flexible, rubber-like material.

Why it's used: Makes parts that bend, compress, and absorb impact. Phone cases, gaskets, tires, shoe soles.

Temperature: 220-250°C nozzle, 40-60°C bed.

Print requirements: Direct drive extruder strongly recommended (Bowden can work but it's difficult). Slow print speed (20-30mm/s). No retraction or minimal retraction.

When to use it: Anything that needs to flex. Phone cases, drone bumpers, wheels, seals, vibration dampening feet.

Limitations: Difficult to print on Bowden setups. Stringing is hard to eliminate. Sticks too well to beds. Not for structural parts.

Variants: TPU comes in different shore hardness ratings. 95A is standard (stiff rubber); 85A is softer; some go as soft as 70A.

Nylon: The Strong Stuff

What it is: Polyamide, known for exceptional strength and durability.

Why it's used: Extremely strong, abrasion-resistant, and slightly flexible. Good for gears, hinges, and functional mechanisms.

Temperature: 240-270°C nozzle, 70-100°C bed.

Requirements: Enclosure recommended. Must be dried before use (Nylon absorbs moisture aggressively). Garolite bed or PVA glue stick for adhesion.

When to use it: Gears, bushings, hinges, structural components, mechanical parts that see wear.

Limitations: Difficult to print. Warps. Requires drying before use. Expensive. Poor layer adhesion if not printed hot enough.

Variants: PA-CF (carbon fibre filled, stiffer, easier to print), PA-GF (glass fibre), PA6, PA12 (different nylon formulations with varying properties).

Specialty Filaments

Wood-filled PLA: PLA with wood particles. Smells like wood when printing. Can be stained and sanded. Weaker than pure PLA.

Metal-filled PLA: PLA with metal powder. Heavy, looks metallic. Can be polished. Abrasive to nozzles.

Carbon fibre filled: Available in PLA, PETG, Nylon. Stiffer, more dimensionally stable. Abrasive — use a hardened steel nozzle.

PVA: Water-soluble support material. Used for complex multi-material prints with dual extrusion. Expensive and moisture-sensitive.

HIPS: Dissolves in limonene. Alternative support material for ABS prints.

Choosing the Right Filament

Display model, prototype, decorative item: PLA. Cheap, easy, good detail.

Functional part, mechanical component, outdoor use: PETG for simplicity, ABS/ASA if heat resistance matters.

Flexible part, case, bumper: TPU.

High-stress mechanical part, gear: Nylon (if you can print it) or PETG for simpler printing.

Outdoor application: ASA (UV-stable) or PETG (good enough for many applications).

Storage and Drying

All filament absorbs moisture over time. Wet filament pops, bubbles, and produces poor quality prints.

Storage: Keep filament in sealed bags with desiccant packets. A dry box or filament dryer is better.

Drying: PLA: 45-50°C for 4-6 hours. PETG: 65°C for 4-6 hours. ABS/ASA: 80°C for 2-4 hours. Nylon: 70-80°C for 6-12 hours (or use a dedicated filament dryer).

The Beginner's Starting Point

Buy a roll of decent PLA. Print your first dozen projects. Then try PETG. Add TPU when you need flexibility. Move to ABS/ASA only when you have an enclosure and need the heat resistance. Nylon and specialty filaments come later.