Have you seen pipes that either have a beautiful dense coloring that seem to have a layer of clear on top of the color? That is generally created by using frit. So what is frit? Frit is crushed glass that is ground up to a very fine, almost sand like consistency. It comes in different thicknesses but generally very small. The frit is the melted into a tube of clear glass until the two different materials become one. The colors come out very vibrant!