Why pay the big bucks for professional tooling gel coats when you can just buy the ingredients to add to your resin.
You can just mix it as you need it and then use the same resin to make your part.
It delivers you an extremely hard wearing gel coat.
Mix with epoxy laminating resin to turn it into a thixotropic tooling gel coat that has almost zero shrinkage when cured.
Mix approximately 2 parts additive to 1 part resin by volume.