Filament Materials Guide: PLA, PETG, ABS, Nylon
The choice of filament material determines mechanical performance, post-processing options, and print reliability more than almost any other variable in FDM 3D printing. The four most common families — PLA, PETG, ABS, and nylon — cover the majority of desktop prototyping requirements, but they behave differently in the printer and as finished parts.
PLA — Polylactic Acid
Composition and properties
PLA is a thermoplastic derived from renewable sources such as corn starch or sugarcane. It is the most widely used FDM filament because it prints at relatively low temperatures (195–220 °C nozzle, 25–60 °C bed or unheated) and exhibits low warping on most surfaces. Tensile strength values for standard PLA typically fall in the range of 45–65 MPa depending on infill, print orientation, and manufacturer formulation.
The heat deflection temperature (HDT) of standard PLA is approximately 50–60 °C under load — low enough that parts left in a car in summer can deform. This limits PLA to applications where thermal exposure is controlled.
Where PLA is used
Concept models, visual fit-checks, presentation prototypes, short-term jigs. PLA is well-suited to the early stages of product development when geometry and proportion are being validated rather than mechanical performance. Its dimensional accuracy is generally good because low thermal gradients during printing reduce internal stress.
PLA is biodegradable under industrial composting conditions (EN 13432), not in standard composting bins. In a workshop environment, PLA scraps can be disposed of with general plastic waste in most Polish municipalities, but should not be represented as environmentally neutral.
PETG — Polyethylene Terephthalate Glycol
Composition and properties
PETG is a modified form of PET (the polymer used in drink bottles) with added glycol to reduce brittleness and improve printability. Nozzle temperatures of 230–250 °C and a heated bed at 70–85 °C are typical. PETG has better chemical resistance than PLA and an HDT closer to 75–85 °C, making it suitable for applications where PLA would deform.
Layer adhesion in PETG is notably strong — parts often fail through the body of a layer rather than at the layer interface, which is less common with PLA. This also means PETG sticks firmly to glass print surfaces and requires a release agent or PEI sheet to prevent damage when removing prints.
Where PETG is used
Functional enclosures, clear or translucent parts (PETG takes dye and is available in transparent variants), food-contact parts (check manufacturer certification for food-safe grades), and mechanical parts where moderate impact resistance is needed. Common in workshops printing brackets, cable management components, and tooling inserts.
ABS — Acrylonitrile Butadiene Styrene
Composition and properties
ABS was one of the earliest FDM filaments and remains widely used where its specific properties — machinability, acetone smoothability, HDT around 90–100 °C — are required. It prints at 230–250 °C nozzle and requires a heated enclosure or at minimum a heated chamber to prevent warping on large flat surfaces. Unenclosed ABS printing in a cold workshop produces consistent layer cracking and delamination.
The main advantage of ABS is that acetone vapour smoothing produces near-injection-moulded surfaces without sanding. Parts can be glued with ABS dissolved in acetone (ABS slurry) and machined on a mill or lathe to remove witness marks or refine dimensions.
Where ABS is used
Production-equivalent prototypes for client demonstration, electrical enclosures (check flammability rating — standard ABS is not rated), tooling masters for silicone mould making, and parts that will receive acetone finishing. In Polish manufacturing, ABS is frequently chosen for prototype automotive interior trim pieces because surface quality after vapour smoothing is comparable to moulded parts.
Nylon (Polyamide)
PA6, PA12, and reinforced variants
Nylon filament encompasses several chemistries. PA6 (Nylon 6) and PA12 (Nylon 12) are the most common in desktop FDM. PA12 absorbs less moisture than PA6, making it more dimensionally stable in humid environments. Both require nozzle temperatures of 240–260 °C, an enclosure, and dry filament storage — nylon is hygroscopic and wet filament produces bubbling, stringing, and inconsistent layers.
Carbon-fibre reinforced nylon (PA-CF, PA12-CF) adds stiffness at the cost of abrasiveness, requiring hardened steel nozzles. Tensile strength in the print direction can reach 80–100 MPa in well-optimised PA-CF parts, approaching the range of short-fibre injection-moulded composites.
Where nylon is used
Load-bearing parts, living hinges, snap fits, gears, and components subject to repeated flexing. Nylon's fatigue resistance outperforms PLA and PETG in cyclic loading applications. End-use production jigs — drill guides, assembly fixtures, gauge blocks — in small CNC machining shops in Poland are frequently printed in PA12 or PA12-CF to tolerate repeated handling.
Comparison table
| Property | PLA | PETG | ABS | PA12 |
|---|---|---|---|---|
| Nozzle temp (°C) | 195–220 | 230–250 | 230–250 | 240–260 |
| Bed temp (°C) | 25–60 | 70–85 | 90–110 | 70–90 |
| Enclosure needed | No | Recommended | Required | Required |
| Tensile strength (approx.) | 45–65 MPa | 45–55 MPa | 40–50 MPa | 50–70 MPa |
| Heat resistance (HDT) | ~55 °C | ~80 °C | ~95 °C | ~110 °C |
| Moisture sensitivity | Low | Low | Medium | High |
| Post-processing | Sand, paint | Sand, paint | Acetone smooth | Sand |
Property values are typical ranges from published material datasheets. Actual results vary with printer configuration, slicer settings, and filament lot.
Specialty materials
Beyond the four main families, several specialty filaments address specific needs. TPU (thermoplastic polyurethane) produces flexible parts — seals, gaskets, protective bumpers — with shore hardness typically in the 85A–95A range. ASA (acrylonitrile styrene acrylate) is an ABS alternative with improved UV resistance, relevant for outdoor-mounted components. Polycarbonate (PC) has high impact resistance and heat resistance above 110 °C HDT but requires temperatures above 280 °C and a fully enclosed, heated chamber.
Composite filaments with short glass or carbon fibre improve stiffness-to-weight ratio but require hardened nozzles and careful slicer settings to manage fibre distribution. They are not a substitute for continuous-fibre composite processes such as Markforged's DFAM system, which uses continuous strands and produces substantially higher mechanical properties.
References: Material datasheets from Prusament, Fillamentum, and FormFutura (all publicly available). ISO/ASTM 52900:2021. UL Prospector polymer database.