Priming, Filling, and Firing

Here are five points to remember when using Colour de Verre molds:

1. Colour de Verre molds must be primed before every use. We only recommed two products for this: Hotline Primo Primer and MR-97. To learn about these products and how to use them, read Tricks of the Trade and Advanced Priming with Boron Nitride. (We have helpful videos for both MR-97 and Primo Primer.) Both products can be purchased on this website. Firing a Colour de Verre design without first priming it could easily ruin the mold. 
2. Every mold has a specific fill weight. This is the amount of frit that you place in the mold for an optimal casting. Fill weights can be found on the products' labels or inserts. If you have lost that information, check out Fill Weights at a Glance.
3. Our molds should never be heated faster than 350ºF (195ºC) per hour to no more than 1450ºF (785ºC).
4. Colour de Verre molds should never be filled with float glass, crushed bottles, or borosilicate glass.
5. Check out our website’s Learn section. It is chock-a-block full of free, downloadable project instructions complete with firing schedules. 

Additional Resources