Alberta Slip Cone 6 Amber Base Glaze

Code: GA6-A
Modification Date: 2019-04-08 16:05:04
Member of Group: AS6

An amber-colored glaze that produces a clean, micro bubble free transparent glass on brown and red burning stonewares.

Alberta Slip 1000F Roasted40.0
Alberta Slip40.0
Ferro Frit 313420.0

Firing Schedule

Rate (F)Temp (F)Hold (Min)Step


This is the base cone 6 Alberta Slip recipe. The 20% frit makes it melt well to form a transparent amber glossy.

Frit 3134 has traditionally been used and it is the best for some additions (e.g. rutile for floating blue). However we recommend Frit 3195 when possible, it imparts a lower thermal expansion for better fit (less crazing). For use on P300 we recommend Ferro 3249 (or Fusion F-69) for the lowest possible thermal expansion.

This base can be used as-is (with no colorant or variegator additions). It is most useful to replace regular transparent glazes on dark-burning clays (to avoid issues with micro bubble clouding). If not cooled slowly, the effect is a very clean, speck free amber transparent glossy that showcases the dark body color below. On light-burning clays and even porcelains, celadon green effects can be produced.

However, if this glaze is cooled slowly (which often happens in heavily loaded kilns) it will form surface crystals. These can produce beautiful effects (depending on cooling speed) that normal clear glazes having added iron oxide powder will normally do. For consistency in appearance it will be necessary to program the descent of your firings to match the slowest natural descent you normally get. Then, on that baseline, you will be able to depend on consistent results. By adding 1% tin oxide you can prevent crystallization (see photo below).

This recipe is excellent base for additions and many of these are documented on the cone 6 glazes page at Glossy brown to black colors require much less stain than does a standard clear base glaze. Reactive rutile and titanium effects that depend on the presence of some iron also react really well with this base.

As noted above, assess the fit with your clay body to be sure there is no tendency to craze (by stressing ware using a 300F-to-icewater IWCT test ice). If crazing occurs switch to frit 3195 (GA6-B). If it still occurs (e.g. with a porcelain), switch to frit 3249. Note again: While these frits still produce the glossy amber transparent effect they may not react the same with colorants, especially the rutile blue.

Glazes having a high percentage of Alberta Slip are most often prepared using the traditional method of simply adding water until the preferred viscosity is achieved (the material has inherent properties that produce functional slurries for dipping). Control of drying shrinkage and slurry character is achieved by varying the proportion roast and raw powder in the recipe. For us, a weight ratio of 88 water to 100 powder (2200 water for 2.5kg of powder) produces a 1.45-specific-gravity slurry that, although fairly runny, gives the right thickness on 1-2 second dip on 1850F bisque-ware (there is some dripping, but coverage is even and it is quick drying). This recipe actually does not respond to flocculant additions that gel traditional mineral-blend glazes to a thixotropic state.

Out Bound Links

In Bound Links

XML to Paste Into Insight

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<recipe name="Alberta Slip Cone 6 Amber Base Glaze" keywords="An amber-colored glaze that produces a clean, micro bubble free transparent glass on brown and red burning stonewares." id="30" date="2019-04-08" codenum="GA6-A">
<recipeline material="Alberta Slip 1000F Roasted" amount="40.000" unitabbr="g" conversion="0.0010" added="0"/>
<recipeline material="Alberta Slip" amount="40.000" unitabbr="g" conversion="0.0010" added="0"/>
<recipeline material="Ferro Frit 3134" amount="20.000" unitabbr="g" conversion="0.0010" added="0"/>
<url url="" descrip="Recipe page at"/>

By Tony Hansen

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