John Britt on Glazes

You might be tempted to read through the glaze recipes in John Britt’s new book, The Complete Guide to Mid-Range Glazes: Glazing & Firing at Cones 4 – 7, and skip the text. Don’t do it. You might think that because you fire at higher or lower temperatures, the book would be of no use to you. Big mistake. The Complete Guide to Mid-Range Glazes is packed with information and belongs on every potter’s bookshelf.

“Iron oxide, “ Britt tells us, “makes up about 7 percent of the top layer of the earth’s crust, and it’s the most common coloring oxide in ceramics. In fact, iron is everywhere on our planet. Technically speaking, all glazes contain some iron.”  Elsewhere in the text he points out, “There are four major forms of iron oxide. These are red iron oxide, magnetic iron, black iron oxide, and yellow iron oxide.” He then goes on to explain the differences between them and how they react in the fire.

Writing of feldspar he tells us that “most feldspars melt at cone 9, the lowest melting feldspar is nepheline syenite, which melts at cone 6.” Each paragrapah is packed with nuggets like these.

Britt also gives an overview of each type of glaze along with its history. In the section on Temmoku he tells us, “During the Song Dynasty (960-1279), the Japanese visited a monastery in a Chinese mountain called Tianmu Shan (Mount Eye of Heaven), where they collected some Jai (oil spot temmoku) tea bowls. The Japanese were inspired to imitate their look. They referred to their highly prized bowls as Tianmu or Temmoku (sometimes spelled Tenmoku.” Later he tells us “Tea dust is a low alumina temmoku glaze that contains magnesium oxide, which is responsible for the yellow-green pyroxene crystals that are of typical of this type.”

Added to this wealth of glaze and materials information, are charts, photos, advice on mixing and applying, and the recipes themselves. Stunning.

Britt devotes an entire chapter to making his argument for firing at cone 6, citing savings in time and money and the reduction of one’s carbon footprint. “For functional ware,” he writes, “cone 6 stoneware is an excellent choice because it’s very durable and vitrified…so it can withstand repeated trips into the dishwasher and microwave. Also, glazes can be made that are stable and don’t leach harmful chemicals.” He goes on to share his ideas on how best to move from cone 10 down to cone 6.

The Complete Guide to Mid-Range Glazes is a must for every potter’s reference library. Thank you John Britt for your extensive research and in depth understanding and your ability to explain what you have learned so clearly.

Summer Reading

Summer has traditionally been a time of work overload for potters. In many cultures, it was a time of getting the crops in, irrigating, harvesting, cutting firewood and, in between, firing a whole winter’s worth of pots. In other cultures, summer meant a respite from winter rains so pots could be made and they would actually dry. In more recent years, it became the season of craft fairs with potters hauling their works from one town to another.

But stretching out in a hammock with a good book? Curling up in the old wicker chair on the back porch and spending hours reading? Certainly potters deserve this indulgence, this opportunity for quiet moments to take in an author’s works as much as vacationing nine-to-fivers do I suspect however, that even though a stack of must-read books calls, many potters feel compelled to stay in the studio.

So I have been delighted with the Summer Reading thread on John Britt’s popular Clay Club blog. What started with a recommendation for the Steig Larson bestselling mysteries has turned to pottery related books. Yes! You could even say, guilt free reading (not that anyone should ever feel guilt for reading…).

Summer, it seems to me, might be the time for fiction and memoir (I know, recently there has been evidence that some memoirs ARE fiction, but surely not potter’s memoirs). For fiction, we saw the YA A Single Shard on the Clay Club. May I also suggest Jose Saramago’s The Cave about an elderly potter who just wants to keep making his pots. Saramago, who was awarded the Nobel Prize for literature in 1998, died a year ago. All of his works are worth reading, but this in my ceramic heart, is his best.

Potters have written quite a few memoirs. One that I go back and reread over and over, at least parts, is The Invisible Core by Marguerite Wildenhain, published in 1973. She writes, “The war was still on, and I had been about a year and a half at work when one day I happened to run into the workshops where the model-makers were throwing models on the potter’s wheel. I was simply hypnotized, and in that second I decided that that was what I was going to do, not those stupid flower designs on vases.” Stubborn and determined throughout her live, she followed through, often under very difficult circumstances, never doubting herself (or her talent). The Invisible Core takes us through her youth, the war years, to Pond Farm, the rural California hilltop pottery where she worked for the last thirty years of her life, often alone, and without sufficient funds, but an inspiration and tough teacher to the students who followed here there. Sadly, the book is out of print, but there is an abundance of used copies available online. I worry what this means. Aging hippy-potters sent to nursing homes or the grave, their personal libraries bought by dealers? My copy has a torn jacket. Maybe I’ll try to find a better one.

Meanwhile, check out the ongoing summer reading suggestions on the Clay Club if you haven’t already.