A chopped strand mat formed of bundles reinforcing fibers and individual reinforcing fibers is provided. The chopped strand mat may be engineered to contain pre not selected amounts of bundles of reinforcement fibers and/or individual reinforcement fibers to select or enhance a particular feature of the chopped strand mat. In at least one embodiment, the reinforcing fibers are wet use chopped strand glass fibers. The reinforcing fibers are at least partially coated with a size composition that maintains bundle integrity during the formation of the mat and assists in filamentizing the bundles during subsequent processing steps in order to form chopped strand mat that gives an aesthetically pleasing look to the finished product. The retention of fiber bundles within the chopped strand mat creates a mat with a higher glass content per volume than conventional dispersed fiber mats. This increased glass content provides improved mechanical and impact performance to the final products.