Blending the Controlled and the Capricious
by Dick Lehman
From the beginning of my involvement with clay, I have been drawn to
pots in which two paradoxical qualities are present: 1) pots which are
carefully crafted, disciplined and controlled, and 2) pots which are
at the same time almost magically affected by the uncontrollable, unrepeatable
and capricious qualities of the firing process.
It probably comes as no surprise that these affections let me early
to raku firing. And here a brief story warrants retelling:
Several years ago I hosted a visiting Canadian potter to three days
of raku firing at my studio. Having limited time we decided to fire
on day two, in spite of some very stormy weather. By dashing out to
the kiln between cloudbursts we mostly avoided getting soaked. However,
at the moment of moving one of my larger pots from the kiln to the post-firing
reduction container, a tornado touched down several miles away. Moments
later a resulting gust of wind toppled the container, and my prized
pot rolled down a dirt embankment into a large clump of wet grasses.
Cursing my luck I retrieved the pot, re-covered it, and waited with
dismal certainty for it to cool and confirm its almost-certain demise.
But to my surprise I discovered a colorful photo-like image of the wet
grasses on the side of the pot.
That serendipitous discovery led me to an intentional pursuit of fresh
leaf images on raku pots. Over time I was able to coordinate imaging
with almost photographic clarity over the otherwise unpredictable copper
Eventually I was introduced to low-temperature salt-firing and contemporary
saggar-firing. Eighteen months ago I decided to attempt to combine parts
of three firing technologies: to link what I had learned from the organic
imaging of raku firing with the two firing procedures mentioned above.
The results, while slow in developing, have been tremendously exciting.
First, a little background: "saggar" is a term used for any structure
which encloses a pot during firing: it could refer to a large lidded
pot which houses a smaller pot. Even an enclosure of stacked bricks
with a kiln-shelf-lid would qualify as a "saggar."
In times when kilns were fired only with "dirty-firing" wood or coal,
saggars were sometimes used to protect the pot from the undesirable
residue of the combustion process. With the advent of cleaner-burning
fuels, the necessity for saggars diminished.
I usually use a stacked-brick enclosure in my car kiln as a saggar.
On the kiln-shelf-bottom I lay down 5-10 cm of fine sawdust. Next I
take bisqued pots and press them into the sawdust to create impressions.
(To vary effects of the firing I press pots in right-side-up, upside-down,
sideways, touching one another, and balanced on top of one another.)
Freshly picked leaves, flowers and grasses are laid into the impressions,
and pots are placed on top of the organic material. Rock salt and metallic
salts (I use mostly copper sulfate and cobalt sulfate) are sparingly
sprinkled adjacent to, and on top of, the pots.* More sawdust and leaves
sometimes follow. Often at least one-third of the pot remains uncovered.
Tight-fitting kiln shelves serve as a lid to the saggar. I use guide
cones placed atop the saggar for firing. While the temperature inside
the saggar is always lower than the guide cone, routine use of cones
outside the saggar leads to relative consistency inside the saggar from
firing to firing. I have always had pleasing results and repeatable
leaf imaging at a wide firing range from cone 08 to cone 10
although I prefer the lower end of this range.
I have used natural gas-fired car kilns, propane-fired raku barrel-kilns,
and top-loading electric kilns for saggar-firing all with fine
results. (If you use an electric kiln, be sure to have adequate ventilation
in and around the kiln; saggar firings have no measurable effect on
shortening the life of electric elements.)
Sometimes the effect of the firing and cooling will cause the surface
layer of clay to craze (a process called "dunting"). To the extent that
it reveals something about the process, I find dunting a tasteful decorative
force. And it in no way compromises the structural integrity of the
Within this process the potter who uses saggars creates a setting,
an opportunity...an "atmosphere"...where the magic of the firing may
do its work. The range of colors, tones, and color-shapes the
deep carbon blacks, the pastel hues, the varying specificity of the
leaf-imaged areas all are determined by the saggar stacking procedure,
the materials used, the temperature of the firing, and the amount of
oxygen available in the saggar. Each firing is different, but equally
This procedure allows controlled, carefully crafted pots to be subjected
to a process which contains limited controls; a process which, in large
part, invites the magic of variables and imprecision to have the final
This blend of paradoxical forces leads to, in my way of thinking, both
the most enlivening pots, and the most passionate and productive lives.
Dick Lehman, along with 11 other producing artists and craftsmen, maintains
his studio in a late-19th-century factory building (called "The Old
Bag Factory") in Goshen, Indiana, USA. He recently hosted Australian
potter Audry Yoder Heatwole for a 10-week studio exchange.
*As metallic salts are soluble and extremely toxic, careful safety
controls must be in place to limit any exposure via respiration or touch.
Responsible clean-up and waste disposal is incumbent upon all artists
who use toxic materials.
This article has been reprinted from the 1990, Volume
29, Number 3 Issue of Pottery In Australia Magazine.
© Dick Lehman, 1990. All rights reserved.