High Calcium Semimatte 2 (Mastering Glazes)
Recipe
Notes
In Mastering Cone 6 Glazes, High Calcium Semimatte 2 (HCSM 2) is the closely related sibling to HCSM 1. It was formulated to offer a slightly "stiffer" melt. Key Properties • Visual Appearance: A soft, opaque, eggshell-white base. Compared to HCSM 1, it tends to be a bit more opaque. • The Science: Like its predecessor, it relies on high calcium levels to create a micro-crystalline surface. • Surface: It is a true semimatte. It isn't quite as "shiny" as a semi-gloss, but it isn't "stony" or dry either. • Durability: This glaze is a gold standard for chemical stability. It easily passes a "lemon test" (acid resistance) and "dishwasher test" (alkali resistance). Likes (Pros) • Opacity: HCSM 2 is often the better choice over HCSM 1. • Consistency: Less prone to "shivering" or "crazing" than more experimental matte recipes. • Color Response: The opacity of the base creates "solid" opaque colors (like a pastel mint or a solid pink). • User-Friendly Application: It stays suspended well and creates an even coat on the biscuit ware that doesn't crack as it dries. Dislikes (Cons) • Cooling Dependence: Use a controlled slow-cool to grow the crystals and avoid it firing glossy. • Flatness: It can look a bit "flat" or "industrial" if used without colorants or texture. It doesn't "break" over edges. • Potential for Metal Marking: As with all high-calcium mattes, the microscopic surface crystals can be harder than stainless steel, producing cutlery marks. • Application Depth: If applied too thinly, it can feel rough.
Description
Base from Mastering Glazes book page 89