GLOSSARY
ABS Filament
ABS (acrylonitrile butadiene styrene) is the strong, heat-resistant filament Lego bricks are made of. Prints at 230–250°C, warps badly without an enclosure, emits styrene fumes.
Definition
ABS is a tough thermoplastic with a glass transition around 105°C. It tolerates impact, sands cleanly, dissolves in acetone (which makes vapor smoothing possible), and has been an industrial standard for injection molding for decades.
On an FDM printer, ABS extrudes at 230–250°C with a hot bed (100–110°C). It contracts significantly as it cools — that contraction is why ABS warps and why an enclosed print chamber is almost mandatory for parts taller than a few centimeters.
Why it matters
ABS is the right material for parts that live in cars, in the sun, in mechanical assemblies, or anywhere ambient temperature could exceed PLA's 60°C threshold. It is also the only common filament that vapor-smooths to a glossy finish in acetone.
Common confusion
ABS emits styrene during printing. The smell is distinctive and the long-term exposure is not great for you — print in a vented enclosure or a separate room. ASA is a near-equivalent material with much milder fumes and better UV resistance.
For most users in 2026, PETG or ASA are better default choices than ABS. Reach for ABS specifically when you need acetone vapor smoothing or its mechanical properties at elevated temperatures.