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Ceramic Art Lesson Plan: Making Sprigs

Posted By Judi Munn On July 30, 2010 @ 2:53 pm In College Level Ceramics Assignments,Education,Lesson Plans 6-8,Lesson Plans 9-12 | No Comments

Goals



• Research historical and contemporary
ceramic works that incorporate sprigging
as part of the surface decoration.

• Learn to make both bisque and plaster
sprig molds.

• Create sprig molds from found objects
and from shapes and designs created in
clay or carved from plaster.

• Apply press-molded sprigs to leather
hard forms, and press sprig molds directly
into forms to stamp the surface.

 

Sprig molds provide a great way to decorate your work. Made from fossils, shells, found objects, or by carving into clay, there’s no limit to the variety.

Sprig molds provide a great way to decorate your work. Made from fossils, shells, found objects, or by carving into clay, there’s no limit to the variety.


Download a printer-friendly version of this ceramic art lesson plan here:

 

Terms
Sprig: press-molded clay piece added to leather-hard work. Sprigs are created using small molds made of bisque-fired clay or plaster.
Press mold: a mold, usually plaster, into which moist clay is pressed to create multiples.
Undercut: common flaw in plaster or bisque molds, where the clay or casting catches and will not pull free without breaking or distorting. To judge whether a mold of an object will have undercuts, look at the object from above, and slowly move your fingertip from the top of the piece down the side. If at any point the tip of your finger is hidden by the piece, that spot would translate into an undercut in a mold because the object goes from wider to narrower. When cast in plaster, the opening on the mold would conform to the narrower section, making it impossible to remove the form in one piece. Objects with undercuts require multiple-part molds and are not suitable for sprig molds.
Background
Wedgwood Jasperware from England is a wellknown example of sprig-decorated ware. While Wedgwood’s patterns are very delicate and intricate, simple sprig molds can be made using almost any object or hand-modeled relief that does not have undercuts.
I use seashells as a motif even though we live in the land-locked Ozarks. On the surface, this might seem a bit out of place, but a trip to any Ozark stream proves otherwise. The creek beds are littered with fossils such as crinoids, sea fan and brachiopods. So, it’s natural that I use fossils, as well as the seashells. I’m particularly fond of the beautifully spiraled ammonites.
Historically, sprigs were removed from the mold then applied to the pot. You can also press the sprig onto the pot while it is still in the mold, which can either be a gentle press or a deep one that changes the contour of the pot. Doing this requires an interesting shape for the whole sprig mold.
The Process
Begin by using the finest grain clay you have. While porcelain is best, I used fine-grain white stoneware with good results. Sprigs will work best when the piece and the sprigged form are made from the same clay, and when attached at the soft leather hard stage of drying.

 

 


 

Note: Sprigs can be used in several ways. They’ve been used as feet and in a surface decoration on the 7-inch vase shown in image A. On the bottle in image B, sprigs form the handles and glazing highlights a sprig decoration on the side. With the punch bowl in image C, sprigs are used in a repeat pattern around the shoulder of the form. All pieces shown here have been fired to cone 9 in a wood-fired kiln

 


Making and Using Sprigs

1. Shape the exterior of the mold by rolling or tap ping on a cloth surface. To make it easier to hold on to, make the mold long or add a handle to the back. Flatten the front of it, texture may be added by pressing the mold onto a textured cloth or other surface.

Fig.1

Fig.1

2. Spray the object with a releasing agent such as cooking spray or WD-40.
Fig.3

Fig.2

3. Center the object on the mold and press it onto the clay.
4. Carefully remove the object, and don’t disturb the edges. Allow the mold to dry slowly then bisque fire.
Fig.4

Fig.4

5. To apply, press a small ball of clay into the deep part of the mold.
Fig.5

Fig.5

6. Press extra clay on the rest of the mold.
Fig.6

Fig.6

7. Put a small amount of water, or slip, on the backside of sprig. With one hand, press the sprig on the pot from the outside. Apply pressure from both sides by using your other hand to press out toward the sprig from the inside.
Fig.7

Fig.7

8. Pressing the sprig deeply into the pot while the pot is still moist makes it less likely that it will come off in the dying process. This also gives the pot a look of spontaneity.

Tip: If you put too much slop on the back of the sprig, it will ooze out and stick to the mold, which makes the mold stick to the pot. If this happens, just leave the mold in place for 5 minutes or so until it absorbs the moisture, then it will come right off. Molds can also stick when they become wet during use, in which case you’ll need to stop and let the mold dry out before continuing.

Detail shot of fired sprig decoration.


Judi Munn and her husband, John Perry, demonstrate pottery making at the Ozark Folk Center State Park in Mountain View, AR. They can be reached at perry/munnstudio@mvtel.net .Their workshop schedule is available through the Ozark FolkCenter at www.ozarkfolkcenter.com.


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