The painted trace line work is usually added first to the glass with a fine brush called a trace line rigger. This is then refined with a needle and then fired permanently into the glass in the kiln. Shading is then added via matting the glass with paint and working into it with a hog brush or needles. This second faze is then fired. Further additions of paint are then added to enhance the affect and fired again each time. Some sections can require three, four or more painting enhancements and firings.