The most commonly used 3D printing material, these PLA filaments make detailed parts at a low melting point, so they won’t warp as they cool, rarely clog nozzles, and don’t require a heated printer bed. They’re also unlikely to drip and produce plastic strings for a clean finished part. In general, they’re best for printing prototypes instead of load-bearing parts since they’re not as strong as ABS or as heat resistant as PEEK. These filaments don’t emit toxic fumes, which means you can safely print them without ventilation. Print them on a fused filament fabrication (FFF) 3D printer.

Stainless steel-, iron-, copper-, and brass-filled PLA filaments are heavier and transfer heat better than plastic-only filaments. Brush, sand, or polish printed parts for a metallic finish.

Filaments with an annealing temperature can be heat treated to make parts harder, stronger, and better at resisting heat. To anneal, heat your finished part to the listed temperature and then let it cool slowly.

Tensile strength is the best measure of a filament’s overall strength. Similar to the stress applied on a rope during a game of tug-of-war, it’s the amount of pulling force a material can handle before breaking. A higher rating means a stronger filament. A tensile strength of 5,000 psi and above is considered good; 12,000 psi and above is excellent.

Maximum exposure temperature is the point at which a printed part will begin to deform. Above this temperature, your part will start to lose structural integrity. Filaments that can be annealed are also rated for maximum temperature after annealing, which is the new maximum exposure temperature once that process completes.