Cactus is a cool light green underglaze that retains color from cone 05 up to cone 6 with minimal darkening. Above cone 6 the color becomes slightly bluer. Clear glaze brightens the color. Cactus underglaze can be used with zinc or non-zinc glazes without color shift.
Tableware producers must test all finished ware to establish dinnerware status, due to possible variations in firing temperature and contamination.