Comparison
Polymaker ASA vs SUNLU ABS: Which Is Better in 2026?
| At a glance | Polymaker ASA | SUNLU ABS |
|---|---|---|
| Rating | ★★★★⯨ 4.5/5 | ★★★★★ 4.2/5 |
| Price | $25-30 / kg | $18-24 / kg |
| Best for | Outdoor, automotive, and functional parts exposed to sun and weather. | Functional parts that need heat resistance, for printers with an enclosure. |
| Guarantee | Amazon return policy applies | Amazon return policy applies |
| Check Today's Price → | Check Today's Price → |
This decision hangs on one question: does the part live outdoors? ASA is essentially ABS re-engineered for weather — similar strength, similar heat tolerance, but it shrugs off UV where ABS chalks, fades, and slowly goes brittle in the sun. That is the real difference between these two spools. Almost everything else about them is closer than the marketing suggests.
The other gap is money. SUNLU's ABS runs $18–24 a kilo; Polymaker's ASA runs $25–30. If your parts stay indoors, that premium buys you nothing you'll ever notice. If they don't, it's the cheapest weatherproofing you'll ever print.
The picks
Polymaker ASA
UV- and weather-resistant filament for parts that live outdoors.
$25-30 / kg · Amazon return policy applies
Polymaker's ASA earns its 4.5/5 mostly on manners: it has a reputation for printing more reliably than typical ASA, with less of the corner-lifting that makes this whole class of filament infuriating. It's the right call for automotive trim, garden fixtures, mounts bolted to the side of the house — anything that faces sun and rain for years. Two caveats. It still wants an enclosure, and it still puts off fumes you shouldn't be breathing, so plan on ventilation. It's also not a first-roll filament; if you've never fought warping before, expect a learning curve.
SUNLU ABS
Budget ABS for strong, heat-resistant functional parts.
$18-24 / kg · Amazon return policy applies
SUNLU's ABS is the value play at 4.2/5, and for indoor functional parts it's arguably the smarter buy. ABS handles heat that softens PLA — printer parts, brackets near anything warm, housings for electronics — and it post-processes better than almost anything else: it sands cleanly and smooths to a glossy, near-injection-molded finish with acetone vapor. The trade-off is temperament. Without an enclosure it warps badly, and the fumes are strong enough that ventilation isn't optional.
How to actually choose
Run the decision in this order. Outdoor part — sun, rain, a dashboard baking in July? ASA, no debate. ABS will fade and chalk, and no amount of sanding fixes UV damage. Indoor part that just needs strength or heat resistance? ABS, and pocket the difference — across a few spools, that savings adds up. Planning to acetone-smooth for looks? ABS again; the vapor-polished finish is the best cheap post-processing in the hobby. And if a part is both functional and outdoors, buy the ASA. A few dollars more per kilo beats reprinting a faded, brittle bracket next summer.
What you should not do is agonize over print quality between them. Both are well-rated, both extrude fine on a properly set up machine, and both will fail identically on a badly set up one. The filament is rarely the bottleneck here; the environment it prints in is.
Who should skip both
Be honest about your setup first. If you print on an open-frame machine with no enclosure, skip both — you'll fight warping and layer cracking on anything larger than a keychain and blame the filament for what is really a physics problem. Same if your printer sits in a bedroom or living space: ABS and ASA both off-gas styrene-family fumes, and no print is worth breathing them in a closed room. In either case, PETG gets you most of the strength and a good share of the heat resistance with none of the drama, and it's the better answer for beginners anyway.
Bottom line
Indoors, buy the SUNLU and save the money. Outdoors, buy the Polymaker and stop worrying about the sun. And if you don't own an enclosure yet, sort that out before either spool arrives — it's the difference between these filaments being a headache and being genuinely useful.