Unidirectional Weave—Sheets with a unidirectional weave have most of their fibers running in one direction. This weave is preferred when making tubular parts, such as vehicle frames, where linear strength and rigidity are required. Often referred to as nonwoven, these are best for reinforcing applications. However, they’re hard to machine because they may splinter.

Plain Weave—Sheets with a plain weave have fibers that are woven in alternating directions for uniform strength and rigidity in all directions. Easier to machine than carbon fiber sheets with a unidirectional weave, their woven pattern holds the fibers together to limit splintering. Plain-weave sheets are more rigid and maintain their shape better than twill-weave sheets. However, they are not as strong and easy to manipulate as twill- and triaxial-weave sheets.

Twill Weave—Sheets with a twill weave have fibers that are woven in alternating directions for uniform strength and rigidity in all directions. Easier to machine than carbon fiber sheets with a unidirectional weave, their woven pattern holds the fibers together to limit splintering. Twill-weave sheets are stronger than plain-weave sheets. They’re also more flexible, making them easier to manipulate into complex shapes. They will not, however, retain their shape as well as plain-weave sheets.

Triaxial Weave—Sheets with a triaxial weave have fibers that are woven in alternating directions for uniform strength and rigidity in all directions. Easier to machine than carbon fiber sheets with a unidirectional weave, their woven pattern holds the fibers together to limit splintering. Triaxial-weave sheets are stronger and more rigid than plain- and twill-weave sheets. They’re often used to reinforce or create thin composites since you won’t have to use as many layers to achieve high strength. Although they are easier to manipulate than plain-weave sheets, they are not as flexible as twill-weave sheets for making complex shapes.