We choose a palette of colors for the project to most accurately render the design. Generally, we use European "antique" and mouth-blown opal glass whenever possible, although American made opalescent glass is sometimes the best choice. Considerations of lighting often plays an important part in the choice of glass. The degree of transparency of the glass is a key factor. Sometimes, it is necessary to have specific colors blown for us in order to achieve special effects. Michelle chooses all the glass and assigns each space on the cartoon a color.