A frit is a type of ceramic glass. It is a combination of materials that, when melted together, are rendered insoluble and resistant to acid attack. They are, therefore, a means of introducing certain materials into a glaze which would otherwise be toxic. Frits can be used alone as low temperature glazes, e.g. raku and majolica, but generally they form the basis of a glaze recipe. Walker Ceramics offers a large range of frits and for those wishing to incorporate the frits in glaze calculations, molecular formulae are listed.
Lead Frits Glazes based on lead frits produce a shiny, durable finish and give brightness and clarity of colour when used in conjunction with oxides, stains, slips etc. While they can be used on all earthenware clays, they are particularly suitable for red clay.
Borax Frits Borax frits are often used in the production of earthenware glazes when a lead free glaze is required. Slight milkiness, especially at lower temperatures, may be evident over red clays, and the colour response with oxides, etc. is not usually so vivid as with lead frits.
Alkaline Frits Similar to borax frits, alkaline frits are noted for their high soda and potash content. The colour response from copper and manganese is turquoise and purple/brown respectively – typical of this type of frit. Alkaline frits have a high expansion rate which makes them a suitable base for crackle glazes.

The table below lists a detailed summary of the properties of the most commonly used frits.

Product Code Frit Number	Description	Use	CaO	Na2O	K2O	ZnO	PbO	Al2O3	SiO2	B2O3	ZrO2	Mol Wt	Soft Temp°C	Trans. Temp°C	COE Linear
DA4193 KMP4193 Replaces F938	Clear, hard barium borosilicate lead free frit. E/W 1040-1100ºC	DISCONTINUED No Longer Available	0.51	0.19	0.1	0.1		0.2	2.86	0.62	BaO 0.1	308	653	590	64
DA4110 KMP4110 Replaces F3110 & 1078	Unleaded high alkali glaze frit. High expansion. 980-1080ºC	Copper blue and manganese purple glazes. For crackles.	0.29	0.64	0.07			0.02	2.86	0.09		280	575	531	96
DA4124 KMP4124 Replaces F3124	Lead free calciumborosilicate frit. E/W1040-1100ºC		0.68	0.28	0.04			0.16	2.56	0.54		266	622	577	74
DA4171 KMP4171 Replaces F3271 & 1057	Lead free calcium borosilicate frit. E/W 1040-1100ºC	DISCONTINUED No Longer Available	0.486	0.514					2.25	0.768		248	590	558	83
DA9146 KMP9102 Replaces 3302-D & 1085	Dense zircon white Lead free frit. E/W 1040-1100ºC	E/W whites and pastel coloured glazes.	0.46	0.416	MgO 0.064	0.058		0.173	4.04	0.836	0.427	431	628	573	59
DA4064 KMP4064 /3531 Lead Bi-Silicate Replaces F4364	Lead bisilicate frit. Standard low solubility. 950-1050ºC						1	0.085	1.95			349	510	465	72
DA4108 Replaces F4508, F3134 & 1077	Lead free calcium borosilicate frit. E/W 1040-1100ºC	DISCONTINUED No Longer Available Try 60% of 3134-2, 40% 4131 as a substitute blend.	0.68	0.22				0.07	2	0.63		229	618	583	78
DA4113 KMP4113 Replaces F4712	Hard lead free clear borosilicate frit. E/W 1040-1100ºC	DISCONTINUED No Longer Available Try DA4131	0.6	0.27	0.13			0.35	3.5	0.63		353	652	586	69
DA4194 KMP4194 Replaces 5325P, 501E34, 5301 & 1012	Lead free soft sodium borosilicate frit. High expansion 900-1060ºC	DISCONTINUED No Longer Available Try DA4110	0.14	0.66	0.2			0.29	2.96	0.67	F2 0.40	329	559	518	93
DA3134 KMP3134-2 Mix 60:40 with 4131 to replace 4108	Lead free calcium borosilicate frit. 980-1080ºC		0.68	0.32				0.038	1.48	0.64		195			95
DA4131 KMP4131	Lead free sodium borosilicate frit. 1050-1100ºC	General purpose for clear glazes.	0.686	0.314				0.346	3.165	0.68		331	670	608	61