Matsayin strontium carbonate a cikin glaze: frit shine a narkar da kayan da aka riga aka narkar ko kuma ya zama jikin gilashi, wanda shine kayan da aka saba amfani da su don glaze na yumbu. Lokacin da aka narkar da shi zuwa flux, yawancin iskar gas za a iya cire shi daga kayan da aka narkar da glaze, don haka rage samar da kumfa da ƙananan ramuka akan saman glaze na yumbu. Wannan yana da mahimmanci musamman ga samfuran yumbu masu yawan zafin wuta da gajeren lokacin harbi, kamar yumbu na yau da kullun da yumbu na tsafta.
A halin yanzu ana amfani da Frits sosai a cikin gilashin tukwane masu kyau da sauri. Saboda ƙarancin zafin narkewar sa na farko da kuma babban zafin wuta, frit yana da rawar da ba za a iya maye gurbinsa ba wajen shirya kayayyakin yumbu masu sauri. Ga faranti mai yawan zafin wuta, ana amfani da kayan da aka yi amfani da su a matsayin babban gilashi. Ko da an yi amfani da frit don glaze, adadin frit ɗin yana da ƙanƙanta sosai (adadin frit ɗin da ke cikin glaze bai wuce kashi 30% ba).
Gilashin frit mara gubar yana cikin fannin fasaha na frit glaze don yumbu. An yi shi ne da kayan masarufi masu zuwa bisa ga nauyi: 15-30% na quartz, 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 narkewar gubar ba tare da gubar ba zai iya biyan buƙatun mutane gaba ɗaya don yumbu mai inganci da lafiya.