How to Choose the Right Filament

After you pick a 3D printer, the first decision you’ll have to make is what type of filament you want to use. There are several dozen varieties—even setting aside the numerous colors they come in. Wading through them surfaces a string of chemical-sounding names: polylactic acid, polyvinyl alcohol, carbon fiber, and the tongue-twisty thermoplastic elastomers, for example. They go by a dizzying variety of acronyms, ABS, PLA, HIPS, CPE, PET, PETT, TPE, PVA, and PCTPE among them. But don’t be dismayed by this alphabet soup. Only a few types are in common use, and manufacturers tend to eschew overly geeky monikers in favor of more descriptive names alluding to an essential quality of the filament such as flexibility (NinjaTek’s Ninjaflex and Polymaker’s Polyflex, for instance) and strength (Makerbot and XYZprinting both market filaments called Tough PLA, and Ultimaker will soon introduce a tough PLA of its own).

Filament Basics

Filaments used in 3D printing are thermoplastics, which are plastics (aka polymers) that melt rather than burn when heated, can be shaped and molded, and solidify when cooled. The filament is fed into a heating chamber in the printer’s extruder assembly, where it is heated to its melting point and then extruded (squirted) through a metal nozzle as the extruder assembly moves, tracing a path programmed into a 3D object file to create, layer by layer, the printed object. Although most 3D printers have a single extruder, there are some dual-extruder models that can print an object in different colors or with different filament types.

The process of…