These leaf and other texture molds are meant to be used to make an impression on iridized glass or transparent glass. They are not meant to be used with powders or frits filling the designs unless they are noted as such. I like to prefuse my blank with a good bubble squeeze first. You can use Primo Primer. If you use Primo brush it out between firings or it will build up and you will lose some of the design. With ZYP just a slight mist between firings. I then fire the prefused glass on the mold to 1410 for 10 min and then anneal. (This works in my kilns but be sure to find the sweet spot in yours.) I anneal these 2 layer pieces for one hour then 100 degrees to 700 and off. You can slump them with the texture up or down for a different look. Hope you love them. The finished glass pieces from these are great sellers! Be sure to always cut your glass so that it is at least 1/4" inside of your the size of your texture mold.