Tail light covers

I was looking on making custom tailight covers for my tailights. I was just wondering how i would go about doing this, can the be fiberglassed, or will the heat from the lights damage the fiberglass. How should i make them?

Like blackouts? Those are usually made by injected acrylic plastic.

do you know how i would go about making them?

It would be much easier and cheaper to buy blackouts. Some custom metal tailights brackets is a diffrent story though.