Semi-Moist Underglaze 112Semi Moist Underglaze Set #112 The Semi Moist Underglazes, or SMUGs, from AMACO are formulated to behave like watercolors and become more transparent when water is added or more opaque with layered application. They can be blended and diluted to achieve a wide variety of effects. Rated for Cone 04 10. These underglazes must be used with proper glaze to be food safe. This set includes 1 1 2 ounce pans of red, bright yellow, chartreuse, warm green,