Mix these additives with melted plastic, epoxies, or adhesives to make parts stronger and more wear resistant without adding much weight. You can use them in batches to tackle repairs and small parts instead of machining your part from a sheet, bar, or other shape.

Kevlar

Choose these additives when your application is likely to wear down your finished part—they improve a part’s ability to stand up to corrosion, bangs, bumps, and scrapes. They’re also used to reinforce points where honeycomb cores connect to fabric. To start, mix in 1 part Kevlar to 15 parts composite.