Overview  Composites provide the majority of the torsional stiffness in a traditional sandwiched construction ski.  On the other hand, a vertically laminated wood core with grains running lengthwise along a ski provides the longitudinal support, but very little lateral support.   By combining composites with a properly laminated wood core, you achieve stiffness and support in several directions.

The most common types of reinforcements include: fiberglass, carbon fiber and Kevlar.  These types are often referred to as fabrics and they are usually woven with fibers running in various directions.  In general, the strength of the fabric is associated with the fiber direction.  Some patterns include: biaxial, triaxial, or even quadraxial fiber.   This means the fibers are running in 2, 3, or 4 directions, respectively.  By having more fibers running laterally across the ski, you can create a ski with a lot of torsional rigidity. 
 

Preparation   Composites usually come in large sheets of fabric.  Prepare the composite by simply cutting the fabric so that it overlaps the ski's edges by a generous amount as shown.  The excess fabric will be trimmed away during the finishing process.

While in storage, keep the composite as clean as possible.  Store away from areas prone to dust or other particles.