Yes, but they have metal moulds. They use acid or sandblast.
Thanks for the link, but I think I skip the release agent for texturing.
What are the other surface textures you mentioned earlier?
I have tried Frekote matt release agent, but I think it's too thin to make real matte surface. It makes glossy surface a bit duller, but not matt....
Moulds - Where the final parts are laminated or poured.
How to archive matte finish to new shiny fiberglass moulds?
Sanding paper/paste? It leaves marks?