A calcium borosilicate frit (fused, powdered glass) which initiates early melting (like gerstley borate) promoting fuller fusion of other glaze ingredients. With the addition of enough siliceous clay, the chemistry of 3134 is very similar to frit 3124.
First fusion: 1450ºF / 788ºC. Flow/Flux: 1600ºF / 871ºC. cte: 9.47 x 10-6.
For more information on frit 3134, see the Digitalfire.com Reference Library of ceramic materials.