GLOSSARY
PLA Filament
PLA (polylactic acid) is the most common FDM filament. It is plant-derived, prints at low temperatures, has minimal warp, and produces clean visual results — but softens in a hot car.
Definition
PLA is a thermoplastic polyester made from fermented plant starch (corn, sugarcane, cassava). It melts around 180–220°C and extrudes cleanly through a standard 0.4mm nozzle. It is mildly biodegradable under industrial composting conditions but in practice will sit in your closet for years unchanged.
PLA was the first filament that worked reliably on early consumer printers, and the entire FDM tutorial ecosystem assumes it. If a slicer profile says "default," it means PLA settings.
Why it matters
PLA is the right choice for visual prints, prototypes, gifts, tabletop figures, and anything that lives indoors at room temperature. It prints with no enclosure, sticks to most beds with minimal fuss, and produces sharp detail.
Glass transition temperature is around 60°C — that is when PLA softens. A part left in a parked car in summer will deform. PLA is also brittle compared to PETG or ABS; it cracks rather than flexing under load.
Common confusion
"PLA+" or "Tough PLA" from various brands are PLA blended with impact modifiers. They are stronger and slightly more flexible than basic PLA, but still soften at low temperatures. For functional outdoor or mechanical parts, step up to PETG, ABS, or nylon.