A Clear Glaze 271D is popular glaze that fits Macs White, Primo PW20, Primo Low Fire Porcelain and other pure white clays and also Primo Red Brown Terracotta and Macs Red and most terracotta clays . Firing range is 1080- 1200+
Clear Stoneware Glaze FS6935
Another clear glaze FS6935 is available that works well on some stoneware clays such as Potters Clay White, Macs Whitestone, and Keane stoneware 33. Firing Range 1200 - 1300.
White Glaze 191D
White Glaze 191D a very white shiny glaze. Recommended firing range is 1080 to 1180 but I have fired higher.
Also - I have mixed 191D with 271D to give a slightly less intense white. Maybe worth a try if you are not after such an opaque white and you are feeling brave!!
Several Abbots Glazes are avaialble. Some available in store and others can easily be ordered in.