This causes the frits to be more reliable in consistently reproducing glazes. here at the ceramic shop, we carry two different general types of frits in the ferro frit line -- boron and alkaline. boron-based frits are typically used in earthenware glazes when a lead-free glaze is required. Alibaba offers 119 acid resistant porcelain enamel products. about 24% of these are other inorganic chemicals. a wide variety of acid resistant porcelain enamel options are available to you, such as free samples. Alibaba offers 94,925 black glaze products. about 31% of these are tiles, 5% are windows, and 1% are ceramics. a wide variety of black glaze options are available to you, such as acid-resistant, antibacterial. Alibaba offers 478 enamel frit glaze products. about 46% of these are ceramics, 5% are building glass. a wide variety of enamel frit glaze options are available to you, such as industrial ceramic, ceramic decorations, and structure ceramic.