If you’re looking for a tough, UV-resistant, and weatherproof filament for your 3D printing projects, ASA might be exactly what you need.
Often compared to ABS, ASA (Acrylonitrile Styrene Acrylate) offers similar strength and durability with one major advantage—it performs much better outdoors.
In this guide, you’ll learn everything you need to know about ASA filament, how it compares to ABS, and how to successfully print and finish your ASA projects for professional-quality results.
What Is ASA Filament?
ASA stands for Acrylonitrile Styrene Acrylate.
It is a thermoplastic polymer developed to provide high strength, chemical resistance, and superior outdoor weatherability compared to traditional ABS.
Key Features of ASA:
- UV-resistant (won’t yellow or degrade in sunlight)
- Highly impact-resistant
- Strong and rigid
- Chemical-resistant
- Water-resistant
- Excellent thermal stability
ASA is widely used in:
- Automotive parts (mirror housings, trim pieces)
- Outdoor signage
- Garden tools
- Drone parts
- Any outdoor functional parts
ASA vs ABS: What’s the Difference?
| Feature | ASA | ABS |
|---|---|---|
| UV Resistance | Excellent | Poor (yellows in sunlight) |
| Weather Resistance | Excellent | Moderate |
| Strength | Very High | High |
| Impact Resistance | High | High |
| Flexibility | Moderate | Moderate |
| Warping | Moderate to High | High |
| Smell During Printing | Strong but slightly less offensive than ABS | Strong and unpleasant |
| Ease of Printing | Slightly easier than ABS but still challenging | Challenging |
| Cost | Slightly higher than ABS | Lower |
📌 Summary: ASA is like an improved ABS, especially for outdoor or long-term applications.
Pros and Cons of ASA Filament
| Pros | Cons |
|---|---|
| UV and weather resistant | Requires high bed and nozzle temps |
| Strong, tough, durable | Warps if printed without enclosure |
| Better color stability outdoors | Strong odor during printing |
| Great surface finish (after post-processing) | Slightly more expensive than ABS |
Printer Requirements for ASA
To print ASA successfully, your printer needs:
- Nozzle Temperature: 240–260°C
- Bed Temperature: 90–110°C
- Enclosure: Strongly recommended (to control cooling and prevent warping)
- Heated Chamber (optional): Helps for large prints but not absolutely necessary
- All-metal Hotend: Ideal for long-term high-temp printing
- Ventilation: Good exhaust system or air purifier to manage fumes
Recommended Slicer Settings for ASA
| Setting | Recommended Range |
|---|---|
| Nozzle Temp | 240–260°C |
| Bed Temp | 90–110°C |
| Chamber Temp | 35–50°C (if controlled) |
| Layer Height | 0.2 mm (0.3 mm for faster prints) |
| Print Speed | 30–60 mm/s |
| Cooling Fan | OFF or very low (10–20%) |
| Wall Count | 3 or more for strong parts |
| Infill | 20–40%, depending on application |
Tips:
- Use a brim or raft to help with bed adhesion.
- Set a slow first-layer speed for solid bed contact.
- Avoid sudden drafts—keep the printer enclosed during the entire print.
Best Bed Surfaces for ASA Printing
| Surface | Notes |
|---|---|
| PEI Sheets | Works well, but may need glue stick for easy removal |
| Glass with Glue Stick | Good adhesion and easy to clean |
| Garolite (G10 Sheet) | Excellent for strong bed adhesion |
| ABS Slurry | Old-school method for extreme adhesion on heated beds |
Always check the first few layers carefully—good bed adhesion is critical to prevent ASA warping.
Post-Processing ASA Prints
ASA can be post-processed very similarly to ABS:
- Sanding: Starts with 400 grit, move up to 2000 grit for polishing.
- Acetone Vapor Smoothing: ASA smooths beautifully with acetone vapor, creating a glossy, injection-molded look.
- Painting: ASA holds primer and paint well, especially after light sanding.
📌 Caution: Use acetone vapor smoothing carefully in well-ventilated areas.
Top Brands of ASA Filament to Try
| Brand | Highlights |
|---|---|
| Polymaker PolyLite ASA | Reliable printing, good color choices |
| Prusament ASA | High precision, excellent quality control |
| eSun ASA+ | Affordable, good for beginners |
| 3DXTech ASA | Industrial-grade ASA for demanding parts |
| Fillamentum ASA Extrafill | Premium finish, easy to smooth and paint |
Common Problems When Printing ASA (and Solutions)
| Problem | Cause | Solution |
|---|---|---|
| Warping off bed | Bed too cool or drafts | Increase bed temp, use enclosure, use brim |
| Cracking between layers | Insufficient enclosure heat | Keep consistent ambient temp |
| Surface roughness | Overcooling | Reduce fan speed |
| Strong odor | Natural for ASA | Print in ventilated space or use air filters |
ASA vs PETG: Which Should You Choose?
| Feature | ASA | PETG |
|---|---|---|
| UV Resistance | Excellent | Good (not as good as ASA) |
| Impact Resistance | High | Very High |
| Ease of Printing | Difficult | Easy |
| Flexibility | Moderate | High |
| Surface Finish | Matte or smooth (after smoothing) | Glossy, rubbery |
| Best For | Outdoor parts, UV stability | Impact-resistant indoor/outdoor parts |
Summary:
Choose ASA if UV stability and outdoor durability are critical.
Choose PETG if you want easier printing with decent outdoor performance.
FAQs
Q1: Can I print ASA without an enclosure?
Small prints might succeed without one, but for reliable results, an enclosure is strongly recommended.
Q2: Is ASA filament food safe?
Unmodified ASA is not generally food-safe. Avoid using it for food-contact parts unless certified.
Q3: Does ASA shrink more than ABS?
ASA shrinks slightly less than ABS during cooling but still requires careful printing practices to avoid warping.
Q4: Can ASA prints survive outdoors year-round?
Yes. ASA is one of the best filaments for UV, rain, and temperature fluctuations.
Conclusion
ASA filament is an excellent choice for anyone needing strong, durable, and UV-stable prints, especially for outdoor applications.
While it requires a bit more attention during printing—like an enclosure, high temperatures, and careful bed adhesion—the rewards are exceptionally tough and weather-resistant parts that last for years.
If you are comfortable printing ABS or PETG, stepping up to ASA is a natural next move—and can significantly expand what your 3D printer can create.