The body is buff burning Plainsman M340 (cone 6). The amber colored glaze is 80% Alberta Slip (raw:calcine mix) with 20% of each frit. The white engobe on the inside of mug 1 is L3954A (also glazed inside using transparent G2926B). These frits are producing an amber gloss glaze of high quality. On the outside of mug 1 we see the 3195 version on the white slip until midway down, then on the bare buff clay (the other has the 3249 version). These mugs are fired using a drop-and-soak firing schedule. There is a caution: Frit 3249 has a very low thermal expansion, use it on bodies that craze other glazes (like Plainsman P300), it could shiver on stonewares like this.
Pages that reference this post in the Digitalfire Reference Database:
Ferro Frit 3249, GA6-A - Alberta Slip Cone 6 Amber Base Glaze, L3954B - White Cone 6 Engobe for Plainsman M390, M340, GA6A Alberta Slip base using Frit 3124, 3249 and 3195 on dark body, P300 and M370 mugs with GA6A Alberta Slip (using Frit 3249), A Cone 6 white engobe works miracles on these dark and buff burning bodies
This post is one of thousands found in the Digitalfire Reference Database. Most are part of a timeline maintained by Tony Hansen. You can search that timeline on the home page of digitalfire.com.