John Healey on thu 22 apr 04
This is my first time on this forum. I have been reading some of the
posts and replies and am very impressed with the depth of knowledge of the
I am a beginning sculptor who has primarily been using oil based clay
until recently. I now prefer the feel of water based clay. My question
concerns the color and look of a fired clay sculpture. I've noticed how
many of the terracotta sculptures by the old masters that I've seen in
books and museums have a very similar color, perhaps best described as a
warm brown or beige. To me, it's beautiful. Does anyone know how to
achieved that look? Did they used glazes? (I don't even know what glazes
I'm grateful for any assistance you can provide.
Snail Scott on fri 23 apr 04
At 09:23 PM 4/22/04 -0400, you wrote:
>...I've noticed how
>many of the terracotta sculptures by the old masters that I've seen in
>books and museums have a very similar color, perhaps best described as a
>warm brown or beige. To me, it's beautiful. Does anyone know how to
>achieved that look? Did they used glazes?
That color is the bare clay itself, fired, but not
coated with anything. Terra cotta is generally
defined as a low-temperature (earthenware)
clay with a buff or tan/orange color, but the
color can actually vary quite a bit. The manner
of firing will also affect the final color -
a kiln fired with fuel (gas or wood, etc) will
tend to result in a darker, warmer-colored clay,
especially if the combustion is short of oxygen
('reduction' firing). This is not a major factor
at low temperatures, but it does make a difference.
Clays fired electrically will have a more
predictable color response, and be slightly
lighter, but it's only a small variation at low
The single biggest factor is the composition of
the clay body itself. There are many manufactured
clay bodies, and they all have slightly different
textures and colors. I'd start with suppliers in
your local area. Ask to see fired samples, and
buy a 25# bag to try. It's not too expensive, so
try any that seems to be what you're after.
Unglazed terra cotta can be very beautiful, and
since it's so direct, with no additional processes
or coatings aside from a single firing, it can
allow the artist to focus on the form rather than
the process, and get successful results limited
only by their skill in modeliing the form. You
will no doubt have excellent results very soon.
The main thing to remember is to not build too
thickly - 1/2" or less if possible. Thicker forms
will need to be hollowed out (or pierced) while
stiff but not yet dry, to allow them to dry well
and to fire without trapping moisture (and thus
steam) within the mass of the clay.
There are a number of good books on this method of
working; any brief search will turn up several.
Reno, Nevada, USA