What is the difference between ASA and ABS?

They are the same polymer family with one component swapped. ABS uses butadiene, which degrades under ultraviolet light; ASA replaces it with an acrylate that does not. Everything else about printing them is close enough to be interchangeable.

Is ASA better than ABS?

Outdoors, yes, and it is not close. Indoors the advantage disappears and you are paying more for UV resistance the part will never use. ABS is the cheaper material and prints slightly cooler.

Can you print ASA without an enclosure?

Not reliably. ASA warps as readily as ABS and needs the same still, warm air. If an open-frame printer is all you have, PETG is the more honest choice for the job.

Does ABS really go bad in sunlight?

Yes. Ultraviolet light attacks the butadiene in ABS, and the part yellows, chalks and turns brittle. How fast depends on exposure, but it is a chemical certainty rather than a risk.

Do ASA and ABS need drying?

Both are hygroscopic and both benefit from it. ABS dries at 65-80°C for 2-4 hours, ASA at 70-80°C for around 4 hours. Wet spools of either print rough and string.

ASA vs ABS: one of them survives the sun.

These two print almost identically, need the same enclosure and smooth with the same acetone. The difference worth paying for is ultraviolet light. ABS yellows, chalks and goes brittle in sunlight because of the butadiene in it. ASA swaps that component out and does not. If the part goes outside, that is the whole decision.

SIDE BY SIDE

Nearly the same spool, until you take it outdoors.

Nozzle temp235-255°C220-250°C

Bed temp90-110°C100-110°C

EnclosureRequiredRequired

Needs dryingYesYes

DifficultyIntermediateIntermediate

Typical price, 1 kg$25-45$18-30

UV resistanceHolds colour and strength outdoorsYellows, chalks, turns brittle

Heat resistanceComparable to ABS~100°C deformation

FumesStyrene, ventilateStyrene, ventilate

Acetone smoothingYesYes

Warping riskHigh without enclosureHigh without enclosure

Temperatures, enclosure, drying, difficulty and price come from the ASA and ABS profiles, so this table cannot drift away from them.

ASA WINS

Three jobs where ABS will let you down.

Anything that lives outside

This is the entire reason ASA exists. Garden fittings, roof brackets, sensor housings, mailbox parts, exterior automotive trim. An ABS part in the same place is on a clock.

Parts behind glass in direct sun

A dashboard mount or a windowsill bracket gets ultraviolet without ever going outdoors. Glass cuts some of it, not enough to save ABS over years.

Anything you would rather not reprint

The cost difference on a single spool is small against making the part twice. Where access is awkward, or the part is bonded into an assembly, buy the material that will not need replacing.

ABS WINS

Indoors, the premium buys you nothing.

Indoor parts, where UV never happens

Enclosures, brackets, jigs, interior automotive. The acrylate in ASA is doing nothing for a part in a cupboard, and ABS is the cheaper spool.

Anything you plan to acetone smooth

Both respond to acetone, but ABS is the material every smoothing guide is written against, and it is easier to buy a spool of it locally.

A slightly easier print

ABS runs a little cooler at the nozzle and is marginally more forgiving on the first layer. Neither is easy without an enclosure, but ABS is the gentler of the two.

NO ENCLOSURE · NEITHER

On an open-frame printer, the answer is PETG.

Both of these need still, warm air and both will lift a corner without it. Choosing between them before you have an enclosure is choosing which one is going to fail. PETG handles most of the same functional work, needs no enclosure, and has moderate UV tolerance of its own.

Compare ABS against PETG instead

VERDICT

The one-sentence verdict.

If the part will see daylight, print ASA and stop thinking about it. If it will not, print ABS and keep the difference. And if you have no enclosure, print neither.

Common questions

What is the difference between ASA and ABS?: They are the same polymer family with one component swapped. ABS uses butadiene, which degrades under ultraviolet light; ASA replaces it with an acrylate that does not. Everything else about printing them is close enough to be interchangeable.
Is ASA better than ABS?: Outdoors, yes, and it is not close. Indoors the advantage disappears and you are paying more for UV resistance the part will never use. ABS is the cheaper material and prints slightly cooler.
Can you print ASA without an enclosure?: Not reliably. ASA warps as readily as ABS and needs the same still, warm air. If an open-frame printer is all you have, PETG is the more honest choice for the job.
Does ABS really go bad in sunlight?: Yes. Ultraviolet light attacks the butadiene in ABS, and the part yellows, chalks and turns brittle. How fast depends on exposure, but it is a chemical certainty rather than a risk.
Do ASA and ABS need drying?: Both are hygroscopic and both benefit from it. ABS dries at 65-80°C for 2-4 hours, ASA at 70-80°C for around 4 hours. Wet spools of either print rough and string.

So which should you buy?

Choose ASA if

235-255°C nozzle · 90-110°C bed · enclosure required

Outdoor brackets and mounts
Garden and roof fittings
Automotive exterior trim

The catch: Same warping profile as ABS, plus a stronger smell. Ventilate the room and keep the chamber warm and still.

Typical price $25-45 per 1 kg spool. Needs drying before use.

Full ASA settings ASA on Amazon

Choose ABS if

220-250°C nozzle · 100-110°C bed · enclosure required

Automotive interior parts
Enclosures
Parts that will be sanded or smoothed

The catch: Corners lift off the bed and layers split partway up. The cause is nearly always a draught, not the bed temperature. Enclose the printer and turn the part cooling fan off.

Typical price $18-30 per 1 kg spool. Needs drying before use.

Full ABS settings ABS on Amazon

Before you order either

ASA needs an enclosure. Without one it will warp, and no spool or setting fixes that.
Buy vacuum-sealed with desiccant, and read how to dry filament before the first failed print rather than after it.
Check the published diameter tolerance. ±0.02mm is good; ±0.05mm shows up as inconsistent extrusion whatever you paid.

Not printing it yourself?

If you would rather have the part arrive than pick a filament, upload the model and get a price in both materials.

FDM only, up to 220mm per side, shipping within the United States. Accepts STL, 3MF, STEP, OBJ.

Upload a file for printing

Ownership: 3DPrinterOnDemand is Another Anvil Road property, so we have a commercial interest in it. We are not recommending it as an independent party, and where it cannot print a material we say so and point elsewhere.