How to print with ASA Filament?

ASA is the outdoor 3D printing filament: UV-stable, weatherproof, and heat-resistant to 85°C HDT. It prints like ABS — an enclosure is required — but holds up to sun and rain where ABS and PLA fail. Here's how to print Eolas Prints ASA.

Unlocking the Advantages of ASA Filament: The Ultimate Choice for Outdoor and High-Temperature 3D Printing

What Makes ASA Filament Different from Other Filaments?

When it comes to 3D printing, the choice of filament material can significantly impact the quality, durability, and performance of your final product. Among the various filament options available, ASA (Acrylonitrile Styrene Acrylate) stands out as a unique and versatile material with distinct advantages.

ASA filament offers a unique combination of properties that set it apart from other commonly used filaments like PLA, PETG, and ABS:

• Excellent UV resistance, making it an ideal choice for outdoor applications where parts will be exposed to sunlight for extended periods.
• Impressive heat resistance, allowing it to withstand higher temperatures without deformation or degradation.
• Improved impact resistance compared to ABS, making it more durable and less prone to cracking or shattering.
• Less prone to warping and shrinkage during printing, resulting in more dimensionally stable and accurate parts.

Why Choose ASA for Outdoor and High-Temperature Applications?

ASA filament is an exceptional choice for applications that demand both UV stability and heat resistance. Its unique chemical structure provides inherent UV protection without relying on additives that degrade over time. This makes it particularly well-suited to automotive exterior components, garden fixtures, marine equipment, and any part that lives outside.

ASA Filament Properties and Specifications

Mechanical Properties

• Tensile Strength: 35–45 MPa
• Flexural Strength: 60–70 MPa
• Impact Resistance (Notched Izod): 15–20 kJ/m²
• Elongation at Break: 15–25%

Thermal Properties

• Glass Transition Temperature (unannealed): 100°C
• Heat Deflection Temperature (HDT): 85°C
• VICAT Softening Point: 105°C
• Maximum Service Temperature: 80°C (continuous)

UV and Weather Resistance

• UV Stability: Certified — maintains properties after extended outdoor exposure
• Weathering Resistance: Superior to ABS and standard PLA
• Colour Retention: Excellent — minimal fading under UV exposure

Optimal Printer Settings for ASA Filament

Temperature Settings

Nozzle Temperature	240–260°C
Bed Temperature	90–110°C
Enclosure Temperature	45–60°C (recommended)
Cooling Fan	0–30% (minimal cooling)

Print Speed and Quality

Print Speed	40–60 mm/s
Layer Height	0.1–0.3 mm
Infill	20–40% for most parts
Wall Count	3–4 perimeters for structural parts

Bed Adhesion for ASA Filament

ASA requires careful bed preparation to prevent warping, which is its most common challenge. Recommended approaches:

• PEI sheets — excellent adhesion with hot bed, releases cleanly when cool
• Garolite (G10) — exceptional adhesion for large ASA parts
• ABS/ASA slurry — apply dissolved ASA scraps in acetone to glass bed
• Hairspray or glue stick — on glass beds as a release and adhesion aid

Always use an enclosure with ASA. Drafts and room temperature fluctuations are the primary cause of warping and layer delamination.

Post-Processing ASA Prints

Sanding and Finishing

ASA sands well using standard wet/dry sandpaper. Work progressively from 200 to 400 to 800 grit for a smooth finish. Unlike ABS, ASA cannot be smoothed with acetone vapour.

Painting

ASA accepts most acrylic and enamel paints well. Prime with a plastic-bonding primer for best adhesion and UV durability. The natural UV resistance of ASA means painted parts also hold up better outdoors than painted PLA or PETG.

Gluing

ASA bonds effectively with cyanoacrylate (super glue), epoxy, and plastic welding solvents. For structural joints, use epoxy with surface preparation (light sanding) for maximum bond strength.

Common ASA Printing Challenges and Solutions

Warping

Problem: Corners lifting from the bed during printing.
Solutions: Increase bed temperature to 100–110°C, use an enclosure, add a brim (5–10mm), reduce part cooling to near zero, and check for drafts. For a deeper walkthrough, see our complete guide to stopping warping in ABS and ASA.

Layer Delamination

Problem: Layers splitting or separating.
Solutions: Increase nozzle temperature by 5–10°C, reduce print speed, ensure enclosure is maintaining temperature, and check filament dryness.

Stringing

Problem: Fine threads between parts of the print.
Solutions: Increase retraction distance (3–6mm for Bowden, 1–2mm for direct drive), reduce travel speed, or lower print temperature slightly.

Moisture Sensitivity

ASA absorbs moisture from the air, which causes popping sounds during printing and surface bubbling. Dry filament at 70–80°C for 4–6 hours before use, and store in sealed containers with desiccant.

ASA vs ABS: Key Differences

Property	ASA	ABS
UV Resistance	Excellent (certified)	Poor (yellows and degrades)
Weather Resistance	Superior	Moderate
Impact Resistance	Higher	Good
Acetone Smoothing	Not compatible	Compatible
Print Difficulty	Similar	Similar
Warping Tendency	Slightly less	Higher

ASA vs PETG: When to Choose Which

Property	ASA	PETG
UV Resistance	Excellent	Good (with UV variant)
Heat Resistance (HDT)	85°C	62°C
Print Difficulty	Harder (needs enclosure)	Easy
Warping	Moderate	Minimal
Best Use	Outdoor functional parts	Indoor functional parts, food safe

Real-World ASA Applications

Automotive

• Exterior trim and replacement clips
• Under-bonnet components in lower-temperature zones
• Dashboard and interior housings (UV stable)
• Antenna mounts and external brackets

Marine and Outdoor

• Boat fittings and hardware
• Garden equipment components
• Outdoor signage and fixtures
• Weatherproof enclosures for electronics

Industrial and Professional

• Jigs and fixtures for outdoor manufacturing processes
• Electrical conduit fittings and housings
• Structural prototypes requiring heat and UV stability
• Replacement parts for outdoor machinery

Tips for Professional-Grade ASA Results

• Always dry ASA before printing — even a few hours of exposure affects quality
• Use a fully enclosed printer — the Bambu Lab X1C, P1S, and Prusa XL with enclosure are ideal. If you're choosing a machine for ASA, our enclosed-printer comparison (Prusa Core One vs Bambu P1S & P2S) covers the best options.
• Print with a hardened steel nozzle for long runs — ASA causes more wear than PLA or PETG
• Use a large brim on the first layer for any part with a small footprint
• Monitor enclosure temperature — aim for 45–60°C ambient throughout the print
• Slow the first 2–3 layers to 20–25 mm/s for maximum bed adhesion

Frequently Asked Questions

What is ASA filament best for?

ASA is the best filament for outdoor, automotive, and marine parts that need UV resistance and weatherproofing — garden fixtures, signage, exterior trim, and weatherproof enclosures.

What is the difference between ASA and ABS?

ASA has far better UV resistance (ABS yellows and degrades in sunlight) and slightly less warping. The main trade-off: ABS can be acetone vapour smoothed, while ASA cannot.

Does ASA need an enclosure?

Yes. Like ABS, ASA needs a stable, warm enclosure (45–60°C ambient) to prevent warping and layer delamination during printing.

What temperature should I print ASA at?

Print ASA at 240–260°C nozzle temperature with a bed of 90–110°C and minimal cooling (0–30%).

Why is my ASA warping?

Raise the bed to 100–110°C, use an enclosure and a 5–10mm brim, reduce cooling to near zero, and eliminate draughts around the printer.

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About the author
Sergio Peciña is a qualified Electrical & Electronics Engineer and Eolas Prints' Technical Design Engineer, with over 10 years of experience in 3D printing. He founded the maker spaces at the University of La Rioja and IDIVAL Santander. Every Eolas Prints filament is manufactured in-house in Cantabria, Spain, to ISO 9001 and ISO 14001 standards.

Ready to try ASA filament? Shop Eolas Prints ASA Filament — UV resistant, weatherproof, and made in Spain. Also available as ASA Pellets for pellet-fed printers. Need advice for an outdoor or bulk project? Book a free consultation.