Woven roving is a heavy, coarse fabric that builds up thickness quickly and adds strength. It is popular in boat building especially when used with chopped strand mat. The mat helps the woven roving adhere well to subsequent layers.
Woven roving is best used on large flat areas.
Gun roving is meant to be used with a chopper gun that cuts the strands into small pieces. It is typically used with polyester and vinylester resin.