Matsayin strontium carbonate a cikin glaze: frit shine a riga an narke albarkatun ƙasa ko kuma ya zama jikin gilashi, wanda shine kayan da aka saba amfani dashi don yumbu glaze.Lokacin da aka riga aka narkar da shi cikin juzu'i, yawancin iskar gas za a iya cire su daga albarkatun ƙasa mai ƙyalli, don haka rage haɓakar kumfa da ƙananan ramuka a kan yumbu glaze surface.Wannan yana da mahimmanci musamman ga samfuran yumbu waɗanda ke da zafin harbi da gajeriyar zagayowar harbe-harbe, kamar yumbu na yau da kullun da yumbu mai tsafta.
A halin yanzu ana amfani da Frits sosai a cikin glazes masu kyau na tukwane mai sauri.Saboda ƙarancin zafinsa na narkewa na farko da babban kewayon zafin harbe-harbe, frit yana da rawar da ba za a iya maye gurbinsa ba a cikin shirye-shiryen samfuran yumbu da aka kora cikin sauri.Don ain tare da mafi girman zafin jiki, ana amfani da albarkatun ƙasa koyaushe azaman babban glaze.Ko da an yi amfani da frit don glaze, adadin frit ɗin yana da ƙanƙanta (yawan frit a cikin glaze bai wuce 30%) ba.
Gilashin frit mara gubar yana cikin filin fasaha na frit glaze don yumbu.An yi shi da kayan albarkatu masu zuwa ta nauyi: 15-30% na ma'adini, 30-50% na feldspar, 7-15% na borax, 5-15% na boric acid, 3-6% na barium carbonate, 6- 6% na stalactite.12%, zinc oxide 3-6%, strontium carbonate 2-5%, lithium carbonate 2-4%, slaked talc 2-4%, aluminum hydroxide 2-8%.Samun narkar da gubar sifili na iya cika bukatun mutane don lafiya da ingancin yumbu.