VC Soft Satin 1 with Frit 3134 substituted for Gerstley Borate test tiles. From left: Standard 240 white stoneware, Standard 112 Brown Speckle Stoneware, Stoneward 308 Brooklyn Red Stoneware. The glaze was mixed to a specific gravity of 1.50 and dipped for 3 seconds. An additional dip of 3 seconds is at a diagonal at the top of the test tile.
VC Soft Satin Glossy 1 is a great midrange white glaze that is forgiving and easy to use. It has been my go-to midrange white for almost a decade. Developed by Val Cushing (maybe decades ago?), you can see lots of references to this glaze in books and online. Many report it does well with stains ranging from 2 to 10% mixed in, but I haven’t tested that yet.
I am sharing this post because I had to make changes to the glaze now that Gerstley Borate is no longer available. I’m pleased to report that substituting Frit 3134 for the Gerstley gave the same results for me. I did bump up the bentonite from 2 to 3% as well, to help the glaze stay in suspension and help compensate for the now higher percentage of frits in the glaze .
I know that many are using Gillespie Borate as a substitute for Gerstley, but that hasn’t always worked for me. So I replaced the 14 percent Gerstley one to one with Frit 3134. It wasn’t the most technical change to a glaze recipe, but it worked for me and the glaze seems the same in handling and color effects.
The only other thing I can add to the wide knowledge base around this glaze, is that I once worked at a studio that was adding both the 14% Zircopax and an additional 10% Tin Oxide. That’s a crazy expensive glaze! But it was very bright white and extremely hard and durable at midrange temperatures. If you are not happy with the cool white results of a zircopax glaze and want a more yellow / bright white, you can play around with the percentages of zircopax and tin; maybe try 7% and 7% of each? Or go with all tin oxide. I imagine the glaze would be about the same.
VC Soft Satin Glossy 1 modified with Frit 3134
| Ingredient | Percentage | 1000g batch |
|---|---|---|
| Cornwall Stone | 46 | 460g |
| Wollastonite | 10 | 100g |
| Kaolin (EPK used in this test) | 10 | 100g |
| Dolomite | 12 | 120g |
| Frit 3124 | 8 | 80g |
| Frit 3134 | 14 | 140g |
| Add: | ||
| Zircopax | 14 | 140g |
| Bentonite | 3 | 30g |
Mix all the ingredients dry, then add them to water.
Mix and blend the ingredients with the water, screen through 40 mesh and then 80 mesh screens.
Add water if needed to get to a specific gravity of 1.50. Adjust as necessary for your studio.
Thanks for reading. You might also enjoy:
Pussywillow and Blueberry Hill Glazes
