The art of making and decorating pottery
Clay is a mix of naturally
occurring materials made up
primarily of fine-grained
minerals. Think of very finely
ground up rock. The fine
suspended in water.
Different colors occur in clay
because of impurities in the
clay. Red clay is the results
of Iron Oxide in the clay,
while white clays get their
color from Talc in the clay
The stages of clay
refer to the different
amounts of water
mixed with the
minerals that make
up the clay.
More water makes
the the clay softer
to the touch, less
water makes the
clay harder to the
Slip clay is clay that has 25% clay to 75%
water. Slip clay is used for a couple of
different things. The first is as a glue when
connecting two pieces of plastic or leather
hard clay together. The second is as a
decoration, when different colored slips are
painted on a pot it will leave a chalky
painted design. The final use of slip
clay is as a way to cast ceramic
items in a mold. This is usually
done in production work, like the
plates and mugs that we see
where the same form is used
over and over again.
Plastic clay is used when you are handbuilding with clay. Pinch pots, coil pots, and
wheel throwing are all done at this stage.
Plastic clay is a mix of 50% clay to 50%
water. It is easy to mold by hand, and can be
connected together by scoring and slipping.
You can tell a piece of plastic clay by
squeezing it, if it doesn’t crack, and
is soft between your fingers it is
considered plastic. Plastic clay is
the best time to make unique
forms in the clay. The plastic stage
of clay is also a great time to work
in new textures. By pressing items
into the clay new surfaces will
result, because the clay is
receptive to any texture!
Leather hard clay has 75% clay to 25% water in it.
Leather hard clay can be connected together by
scoring and slipping, but you do need to score
aggressively to get the pieces to stay together.
Leather hard clay is hard and cold to the touch, if
you have a slab of clay and lift it up, it
will not sag down. In this stage, the
clay will crack if you try to bend it.
Leather hard clay is a great
stage to do carving
carved lines well.
Bone dry clay is the final stage before the clay is
fired. Bone-dry clay has 100% clay to 0% water. In
this stage you cannot do any additive method, but
you can do some limited subtractive work. Bone-dry
clay will crack and break if pushed too hard, and is
very fragile to the touch. When clay reaches this
stage, you are usually ready to fire the
work, We call this finished “Greenware”.
If you are not satisfied with
your work, you can reclaim
the clay by letting the clay
soak it in some water. By
letting it sit for a few days
the clay will become slip
clay and start the process
all over again.
Clay in a
Clay must be fired in a Kiln to make it permanent.
The kiln heats the clay up to 2000 degrees to fuse
the minerals in the clay together. When clay
comes out of the kiln after it’s first firing, it is
Bisqueware will not melt
into slip if placed in water,
and is ready to glaze.
Glaze is the shiny, coating we see on most
pieces of pottery. Glaze is made mostly of two
1. Silica a finely ground and pure sand, that gives
the glaze a shiny surface
2. Minerals that give the glazes their colors and
Additive Sculpture Method: When two or more
pieces of clay are pressed together to create a new
form. Pieces that are done with the additive method
should be scored and slipped to make them stick
together. If a piece of clay is not scored and slipped
it will most likely fall off in the firing.
Subtractive Sculpture Method:
When the clay is carved or
pressed into it is considered a
subtractive sculpture method. If
the clay is carved or when clay
is removed from the surface we
call it a subtractive sculpture
Often, a work of ceramic art will have both additive
and subtractive methods used at the same time
For our upcoming clay project, we will be working with a visiting
artist Sonata Kazimieraitiene to create textured tiles that will be
incorporated into the mural we will be installing in the hall outside of
the main office.
One of the great aspects of clay is that is receptive
to any texture, and because of that we can create
many varied surfaces can be impressed into the
Your homework due at your next class is
to bring in one item to use as a texture
tool. The tool you bring in needs to follow
the following guidelines:
1. It can not be an object normally found at school! (no
pen caps, paper clips, markers, etc.)
2. Your tool bust be able to create a texture by rolling or
pressing into the clay.
3. Tools should be from nature, or made of plastic, cloth &
fiber, or metal. No glass, paper, or breakable objects.
Our visiting Artist
Born in Lithuania, Sonata Kazimieraitiene received
an Masters of Fine Arts in Design from Vilnius Art
Academy and worked as a graphic designer and
PR/Marketing specialist. Upon relocating to the
U.S., Sonata has since worked with Terra Incognito
Gallery (Oak Park, IL) and Dole Art Center (Oak
Park, IL) as an instructor and studio member. She
is currently a Studio Artist at Chicago’s Lill Street
Though I enjoy every part of the clay-working process, my current approach
involves a trusting mutual exploration. Clay has its own life, and it can express
what it wants to become in your hands. I just watch, listen, and react. I don’t
demand or stress too much and am not afraid of experimenting. I also try to see
the possibilities in every step, from the beauty of raw clay to the potential of
leftover scraps. Satisfaction comes from realizing I am not in total control, but
rather just one of the components in the process. I am most rewarded and
inspired when I do my best and leave room for the other players - clay, glaze,
and fire - to do their jobs.