Fiberglass matts are used in combination with polyester resin or epoxy.
They are used to reinforce the polyester or epoxy.
A thinner fiberglass matt (less g/m²) is more flexible and easier to apply to shapes with lots of corners.
This is an important factor when planning you project, so keep this in mind.
Fiberglass matt can be used for mold jackets, helmets, shields, armours, statues,..