GA6-A Alberta Slip Cone 6 Base Glaze


The base cone 6 glaze recipe for Alberta Slip, it adds 20% frit to produce a well-melted amber transparent. It is very useful itself as a cover and liner glaze and can become much more if slow cooled (to form surface crystallization) and with additions (e.g. to form cobalt-free floating blue).

Transparent glaze of choice for dark bodies

The amber color and micro-bubble-free matrix make this work so well.

Clear glazes often do not work on dark bodies. The center mug is clear-glazed with G2926B (and is full of bubble clouds). This dark body (M390) is exposed inside and out (the other two mugs have a white engobe inside and midway down the outside). G2926B is an early-melter (starting around cone 02) so it is susceptible to dark-burning bodies that generate more gases of decomposition. Left mug: The outside glaze adds 4% iron to G2926B (the glaze was not screened, so iron particles are agglomerated and acting as a fining agent, removing the bubbles). Right mug: The whole thing is glazed with GA6-A Alberta Slip base glaze (but using Ferro Frit 3195 instead of 3134). These amber glazes have an added benefit: The color darkens over dark burning bodies (to almost black).

Coffee Clay fired at cone 6 with transparent glazes. The Alberta Slip GA6-A glaze (left) is clearly better that the G2926B on the right. This firing is schedule C6DHSC, a 100F/hr slow cool to 1400F. The glaze is the right certainly has fewer bubbles than normal, but still is not nearly as good as the one on the left.


The GA6-A glaze on the insides of these mugs has crystallized during cooling (normally it is a transparent amber). This happened because we programmed the firing to drop at 150F/hr down to 1400F (the GA6-C blue requires it). You can prevent the crystallization during slow cooling by adding 1% tin oxide to the recipe.

Glaze Recipes

You can find the home page for this recipe at by clicking the following: GA6-A. And the cone 6 glaze page at has all kinds of variations (additions of colors, variegators, opacifiers) that can be made.

Alberta Slip as a celadon at cone 6 (left), cone 10R (right). The left recipe is just the base GA6-A with Frit 3195 on Plainsman M370. The other is Alberta Slip/Ravenscrag Slip 50:50 mix on Plainsman P700.

P300 with Alberta Slip GA6-A base glaze. But this employs 20% frit 3249 (instead of 3134) producing a lower thermal expansion.

M340 with GA6-A base Alberta Slip glaze. However this one employs frit 3195 instead of 3134. A slow cool produced a flawless surface.

Safety Data Sheet

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