New 2022 M340S

Coming in November, 2022.


A buff-burning speckled cone 6 stoneware. M340S (old recipe) and M340GS supplies will run out by the end of 2022, this is much better and will replace them starting in November.

New M340S mug fired to cone 6. G2926B white inside and G2934:G2926B 85:15 white outside. Both have 3% tin oxide and 5% Zircopax added.

Process Properties

The new M340S works well with our L3954B engobe. We are not planning a grogged version, this dries well so there is no need for it. In the past the grogged version was not resistant to bloating at cone 6 but this new mix does not require that, because it does not bloat.


Old M340S vs new 2022 M340S (cone 8 down to 4)

New M340S at cone 6. It is less vitreous so will leak if the glaze crazes. If glazes fit it pieces will be water-tight.

An all-new recipe, this fires easily to cone 6 (and even cone 7) while burning to the same color as M340.


The new 2022 M340S with colored glazes fired at cone 6 using the PLC6DS schedule. The white and colored mugs are made using the G2934 base, the clear and purple one using the G2926B base.

There should be no concerns with glazes, use the same ones you have always used.

Logo Plainsman Clays Ltd.
702 Wood Street, Medicine Hat, Alberta T1A 1E9
Phone: 403-527-8535 FAX:403-527-7508