Red Temmoku, the Story of an Obsession
(14 January and 04-06 March, 2001, with later continuations)
Soon after I got involved in pottery I discovered that there were glazes I wanted to use on my pieces, but didn’t find among the ones I had access to. I also discovered that I didn’t really like most of the ones that were available to me. No surprise, I soon found myself trying to mix a few of my own. This page is the story of one of them, a Temmoku variant that I hoped would be a deep rich transparent cherry-mahogany red in bright light, rather than the apparent black of most Temmoku glazes.
Sidebar: Tenmoku vs Temmoku
The term “Tenmoku”, regrettably often spelled “Temmoku” these days, appears to be the Japanese version of Tian mu Shan, “Heaven’s Eye Mountain”, an area in China where tea is grown and teaware was (and perhaps still is) used by monks, but not apparently made. The major styles of teaware that are referred to by the term “Tenmoku” were manufactured in the Jian and Jizhou regions, and transported to many places in China.
Teabowls were brought to Japan, apparently by monks who had visited Tian mu Shan; they became famous, and some of the styles were eventually reproduced in Japan or transformed into Japanese styles. The most familiar of these, at least to us, are the ones with dark, iron-rich glazes; but there were various glazes in use in the two regions, and the name properly refers only to the pottery styles. For the purposes of this page, then, I will use the spelling “Temmoku” to refer to the glazes, both ancient and modern.
[Various books on Chinese and Japanese ceramics have more information, if you’re interested. (I particularly like Hare’s Fur, Tortoiseshell, and Partridge Feathers; Chinese Glazes, by Nigel Wood; and Inside Japanese Ceramics, by Richard L. Wilson.)]
There are a number of common variants, which I won’t get into here; they include oilspot glazes, hare’s-fur and possibly partridge-feather glazes, and (if I’m remembering correctly) teadust glazes, which appear to be dark glazes that haven’t been fired to full maturity.
I strongly suspect that the familiar “Kaki” (persimmon-colored) glazes and the so-called “Russet Ding” glaze are also closely related. This page is not particularly about those things, but I may discuss them elsewhere because I find them interesting.
Just by the bye, if you haven’t seen a kaki glaze and you are only familiar with bright orange persimmons, I should note the fact that many Japanese persimmons are rich orangy brown inside, and that’s what the glaze looks like. (…And if anyone spells it “khaki”, that’s just wrong. Khaki is a fabric color that has nothing whatever to do with iron-rich glazes. The name derives from a word that means “dust” or “dust-colored”.)
To return to the track:
I say apparent black because Robert Tichane relates, in his excellent book on Ash Glazes, that when he looked through a glaze chip from one of the ancient pieces he was surprised to find that it was actually yellowish. The ancient pieces were fired in oxidation, and the body was high in iron, so it fired out to a rather dark color. The combination appears black or extremely dark brown under most types of lighting. Our modern glazes are mostly fired in reduction, so the colors and effects are slightly different, but the glazes can be just as lovely.
For a fine example of a modern Temmoku glaze, have a look at Ron Roy’s work.
As you can see from Ron’s photos, a Temmoku glaze appears glossy and black where it is thick, and “breaks” to some pleasant opaque color, usually a milk-chocolate or peachy brown, on edges and ridges.
This page is actually largely about my being somewhat slow on the uptake, as will become apparent.
First Off, There Ain’t No Such Thing.
I like a number of the variants of Temmoku, and in fact I’ve managed to copy one or two of them since I wrote most of this page; but in particular I wanted something red. Not knowing whether there were any Red Temmoku glazes, as I hadn’t seen any (not to give a whole lot away, I still haven’t, other than my own, and I’ve never seen a photo of one in a book, though I have seen some tomato-orange things that were described as “red”), and not having the least notion of how to create such a glaze, I set out to make one anyway. This is perhaps not a formally approved way to proceed, but we will leave that aside for the moment.
These alone quickly proved insufficient. I did get some nice opaque browns as I started with plain clay and began adding ash; some of them even had tiny reddish crystals in them, which I found attractive and encouraging… they are pleasant glazes, similar to some of the Tanba glazes of Japan or to Kaki, and I’m happy to use them; but they aren’t Temmoku, much less Red Temmoku. When I eventually added too much ash I got a stringy transparent greenish glaze that looked rather like many other typical ash glazes. So far, so good: I wasn’t where I wanted to be, but I was getting good information about the behavior of my materials.
At that point I decided to increase the clay content a bit and add some silica and some red iron oxide, because Temmoku glazes are high in iron and because I figured that some silica might smooth the surface a bit. I also figured that the clay should prevent the legginess that was caused by the ash.
This, however, is where I made a crucial error: I weighed the clay and the ash after running them through a 10-mesh sieve. Then I mixed up the glaze by adding the silica and iron oxide and water. The resulting glaze slip was full of huge chunks of obnoxious crap, and when I ran it through a 60-mesh sieve to get rid of those, I lost an uncertain amount of each material. Once that happened, I no longer had any least notion what the real proportions were.
Double oops: almost needless to say, the glaze was a Red Temmoku, just what I wanted. I’d even managed to make enough to dip a few pieces. It looked about like these images: