Decorating Techniques

ceramic artsdaily.org

three great pottery decorating techniques

a guide to sgraffito, how to make and use terra sigillata, and creating and coloring highly textured surfaces

www.ceramicartsdaily.org | Copyright © 2010, Ceramic Publications Company | Three Great Pottery Decorating Techniques | i Three Great Pottery Decorating Techniques A guide to sgraffito, how to make and use terra sigillata, and creating and coloring highly textured surfaces

Decorating your work before it’s fired provides you with a lot of creative opportunities. At the soft clay stage, you can stamp and texture your clay using many types and kinds of objects. When the clay is leather hard, you can coat your work with colored slips and carve away to create patterns. And when your clay is bone dry, you can apply terra sigillata and burnish the surface to a high sheen.

Scratching the Surface: A Step-by-Step Guide to Sgraffito by Wayne Bates

Sgraffito comes from the Italian word graffito meaning “to scratch,” and Wayne Bates does more than scratch the surface with this informative tutorial on the tips and techniques of getting the best results. Using both cutting and scratching techniques, he demonstrates the finer points of line work, scraping large areas and cross-hatching. If you’re into making your own glazes, he’s provided 19 colorful engobes along with 5 recipes for various clear glazes you can try out.

Burnishing with Terra Sigillata by Sumi von Dassow

Terra sigillata means ‘sealed earth’ and comes from the name of a type of Roman pottery mass-produced around the first century AD. But the Romans copied the Greek technique used in their famous black and red pottery for hundreds of years before that. Here is a complete guide to making and applying terra sigillata, recipes, and troubleshooting.

How to Make a Textured Platter by Annie Chrietzberg

Lana Wilson is the maven of textures and reveals her signature technique for creating a textured platter. In her step-by-step procedure you’ll see how she adds so much character to her pieces and how she brings the clay to life. She also includes her simple glazing technique along with her recipes.

he word sgraffito is de- rived from the Italian word graffito, a drawing Tor inscription made on a wall or other surface (graffito also gave us the word graffiti). Graffito is past participle of sgraffire, which means “to scratch.” So the word sgraffito basically means to scratch and create a graphic or an image. In ceramics, sgraffito is a technique of ornamentation in which a surface layer is incised to reveal a ground of contrasting color. I use sgraffito to get a clean line without masking or rulers, and I Plates, 10 in. (25 do more cutting than scraping. I still moist enough to stick if you cm) square, sgraf- use a handmade tool that is thin touch them to the surface, so they fito decoration and cuts smoothly. I cut when the should be removed frequently. with clear glaze piece is stiff leather hard, which You can use a thin coat of wax fired to cone 5. makes straight lines possible. If resist to protect light-colored areas the piece is bone dry, the cut will from dark cuttings. The wax resist be jagged and brittle. If the piece will burn off in the bisque. is too soft, the tool raises the edge Ball clays are used for engobes of the cut and makes a higher because they are the most plastic ragged edge. clays and shrink the most allow- If your clay has grog in it, or ing more room in the recipe for anything coarser than fine sand, non-plastic color, frit, modifiers you won’t get a smooth cut. I use and fillers. Frit is used to bind a rubber-tipped air tool and a soft the coating to the surface and to cosmetic brush to blow or brush increase the interface with the pot off the cuttings. The cut pieces are and the glaze. Wollastonite is used

I use an automotive-detail-type spray gun to apply engobes and glazes. It has a smaller fan size than the full-size gun, has good volume, and is much faster than an airbrush. It’s a high volume/low pressure (HVLP) gun and it produces less overspray. I use a large HLVP spray gun for the cover glazes because of its high volume.

to add calcium so the chrome-tin colors, i.e., the reds, pinks, and colors will work, and flint is used purples. The molecular recipe has CAUTION as a filler and stabilizer for colors to have three times more calcium Overspray is haz- that flux the mix. I mix the en- than boron for these to work. ardous. The engobe gobes thoroughly and screen them They have that ratio and will spray contains silica, through an 80-mesh sieve. Most produce the right color with all which can be harm- of my colors come from commer- my engobes. I do use barium for ful if inhaled. Wear a cial glaze stains although not all what it does for the colors and for mask, and make sure commercial stains will work, but the matt. The potential problem your booth has an if you think of engobes as being with it has to do with the heavy exhaust system. closer to glazes than slips, addi- metals and the possibility of leach- tives can help produce the right ing. From what I can find out, if a colors. Changes in the frit affects glaze has less than 15% barium in how fluid an engobe is and how the percentage composition, it will it works with the glaze. It can not promote leaching. From the also produce a vitreous, glaze like tests I have done, the glazes that I surface. Changes in the amount now use do not promote leaching of ball clay will make the engobe when used over the engobes. I do more or less plastic and change use a liner glaze for liquid contain- whether it goes on very wet pieces ers and I don’t use the solid color or bone-dry pieces. glazes on eating surfaces. I use a matt and a shiny glaze to I spray very wet, as if I’m cover the engobes on the face of pouring on a small stream of the the pieces and these two glazes are glaze or engobe on the piece. The what I call “color friendly.” To get engobe sets quickly because the as many colors as possible, they leather-hard piece can absorb have to work with the chrome-tin some water, but too much engobe

Place the platter on the wheel over a piece of foam Move the platter to a banding wheel and create and create the center spiral as the wheel turns. freehand marks. 6 7

Scrape off large areas last using the flat side of a rib. Cross-hatching is done with a serrated tool.

and the piece can collapse. If the dry enough, store the pieces on engobe is too thick, it makes the cloth on top of plastic, and place color and the glaze crawl. Set the cloth over them to prevent con- fan for a tall oval and overlap the densation from the plastic marring spray by 50% with the piece on a the color (figure ).3 banding wheel turning smoothly First I create the center spiral through the spray. Practice spray- and circle using a foam rubber ing with paper plates so you can chuck on the wheel (figure 4). All cover the plate smoothly with no the other lines are done freehand bare spots or dusty areas. on a banding wheel (figure 5). The four colors of this color set The scraping of the larger white are black, french green, chartreuse, spaces is done last, when the piece and crimson and are applied from is even harder. I try to take off dark to light (figures 1–2). The only the layer of color (figure 6). spray adds water to the piece and I use the tool tip to make a sort it must dry to the leather hard of ditch that you can scrape to state before it can be carved. When or from to make the larger white

www.ceramicartsdaily.org | Copyright © 2010, Ceramic Publications Company | Three Great Pottery Decorating Techniques | 4 areas. I use the flat side of a rib to smooth some of the cuts and to make the larger cuts. remove small bits of color. There will be some edges that Cross-hatching is another way of can be felt, and glazes will break exposing the white of the porcelain away from these edges, but the and is done with a serrated-edge glaze will fill in to make it smooth- tool (figure 7). I add black dots er than when cut. Small nicks and of engobe using a squeeze bottle. cuts can be patched, but the spray When all the carving is done, the overlaps are very hard to color piece is air-dried then bisque fired, match, so it is best to avoid mis- then a clear satin matt or a shiny takes! When almost bone dry, use glaze is sprayed on the front and 0000-grade steel wool to lightly solid color glazes on the back.

Tools My sgraffito tool tips are made from the main spring of a pocket watch. The spring metal is thin and strong, doesn’t have to be sharpened and keeps the same feel as it wears away. To make the tip, cut a piece of spring, heat it with a small torch and bend it to the shape you want. A small rounded point is used for the line cutting tips, and a broader rounder tip for large cuts. Glue the tip with Elmers glue into the brass ferrule of the trimming tool and allow it to harden. Lightly heating the ferrule softens the glue and the ferrule can be removed and another tip Assorted and modified glued into the tool. For ribs, cut them with tin snips from tools used in sgraffito. sheets of metal and flatten the edges, making two square Detail of trimming tool edges for scraping (do not sharpen the edges). You can with ferrule removed and also cut serrated-edge ribs with the snips. watch-spring cutter formed to desired contour.

Sgraffito techniques can be a lot of fun, es- UBR-17 Seal Brown UGR-10 Silver Gray pecially with a large color palette of engobes. C&C Clay ...... 40 % C&C Clay ...... 60 % Most of my colors come from commercial glaze Nepheline Syenite ...... 20 Ferro Frit 3134...... 10 stains. Frits, fillers, and retardants are added, Wollastonite...... 10 Silica ...... 10 depending on the colorant used. The following Seal Brown #6153...... 30 Silver #6530...... 20 engobes are mixed with Mason stains. 100 % 100 % Engobes UB-18 Teal Blue UPR-32 Deep Orchid C&C Clay ...... 60 % C&C Clay ...... 50 % UBL-45 Black Ferro Frit 3134...... 30 Nepheline Syenite ...... 10 C&C Clay ...... 50 % Teal #6305...... 10 Deep Orchid #6303...... 30 Ferro Frit 3195 ...... 20 100 % Wollastonite...... 10 Black #6600...... 30 100 % 100 % UR-28 Dot Red C&C Clay ...... 50 % UY-38 Hot Yellow UR-31 Crimson Wollastonite...... 20 C&C Clay ...... 50 % C&C Clay ...... 50 % Ferro Frit 3134...... 10 Nepheline Syenite ...... 10 Ferro Frit 3134 ...... 20 Crimson #6006 ...... 20 Ferro Frit 3134...... 10 Wollastonite...... 10 100 % Wollastonite...... 10 Crimson #6006 ...... 20 Yellow #6481...... 20 100 % UBL-46 Blue Black 100 % C&C Clay ...... 50 % UG-35 French Green Nepheline Syenite ...... 10 UW-1 White C&C Clay ...... 50 % Silica ...... 10 C&C Clay ...... 30 % Ferro Frit 3134 ...... 15 Black #6616...... 30 Nepheline Syenite ...... 20 Wollastonite...... 10 100 % Ferro Frit 3134...... 10 French Green #621 ...... 25 Wollastonite...... 10 100 % UB 22-Turquoise Blue White #6700...... 30 C&C Clay ...... 50 % 100 % UG-41 Chartreuse Ferro Frit 3134...... 10 C&C Clay ...... 50 % Wollastonite...... 10 UB-7 Peacock Blue Ferro Frit 3134...... 20 Zircopax...... 10 C&C Clay ...... 40 % Chartreuse #6236 ...... 30 Turquoise #6390 ...... 20 Nepheline Syenite ...... 10 100 % 100 % Peacock Blue #6396...... 40 Wollastonite...... 10 UBL-41 Light Blue Black UP-49 Hot Pink 100 % C&C Clay*...... 60 % C&C Clay ...... 40 % Nepheline Syenite ...... 10 Ferro Frit 3134 ...... 40 UPR-31 Pansy Purple Wollastonite...... 10 Pink #6020 ...... 20 C&C Clay ...... 50 % Silica ...... 10 100 % Nepheline Syenite ...... 10 Black #6616...... 10 Wollastonite...... 13 100 % UP-34 Coral Pansy Purple #6385...... 27 C&C Clay ...... 50 % 100 % UG -69 Turquoise Green Ferro Frit 3134 ...... 10 *C&C clay is a ball clay . If not available, another C&C Clay...... 50 % Wollastonite...... 10 ball clay may be used, but the results may vary . Wollastonite...... 10 Coral #6090...... 30 Although formulated for cone 6, many of these 100 % will work at higher and lower temperatures . Ferro Frit 3134...... 20 Always test new recipes before using . Turquoise #6393 ...... 20 100 %

Glazes The following glaze recipes can be used over the engobes, but they can also be tinted with stains. R-1030 Satin Matt* G-19 Shiny Clear Cone 5 Cone 6 Barium Carbonate...... 11 % Wollastonite...... 30 % Wollastonite...... 15 Ferro Frit 3195...... 30 Ferro Frit 3134...... 19 EPK Kaolin...... 20 Nepheline Syenite ...... 33 Silica ...... 20 EPK Kaolin ...... 16 100 % Silica ...... 6 Color friendly base, will produce shiny versions 100 % of most of the Mason stain colors . Can be used Similar to R-1015 but lower temperature . Will as a liner glaze, unlikely to produce leaching . go shiny if fired higher . Top of my kiln . Frosty Matt R-1012 Satin Matt* Cone 6 Cone 5 Barium Carbonate...... 22 % Barium Carbonate...... 11 % Lithium Carbonate...... 5 Whiting...... 12 Nepheline Syenite ...... 60 Ferro Frit 3134...... 17 EPK Kaolin...... 8 Nepheline Syenite ...... 44 Silica ...... 5 EPK Kaolin...... 7 100 % Silica ...... 9 High alkaline, distinct color characteristics, 100 % crystalline sugar like surface, turns copper Similar to R-1015 but lower temperature . turquoise, brightens most colors. Middle of my kiln . *Contains barium . Can produce leaching when used with heavy metals . No claims made for R-1015 Satin Matt* success or safety . Cone 6 Barium Carbonate...... 16 % Wollastonite...... 15 Ferro Frit 3134...... 13 Nepheline Syenite ...... 33 EPK Kaolin...... 14 Silica ...... 9 100 %

ome potters think of terra sigillata as the easy way Struck by Ricky Maldonado. 15 in. (38 cm) in height. ‘Low- to burnish. Terra sigillata is relatively quick and fire terra cotta clay, coil built, sanded using three grades of sanding sponges, coated with six layers of terra sigillata easy to apply, but there are various potential dis- then burnished with hands using the oil from my body (I Sadvantages compared to stone polishing: it can rub behind my neck or legs). Finished with dry-cleaner plas- crack or peel off after firing; it may be difficult to apply an tic wrapped around my fingers. Design drawn in black slip, absolutely smooth coat without brush marks or drips; it then dots applied using low-fire glaze between the lines. will reveal all texture on the surface it is being applied to, Fired to cone 06.’ for good or ill; and it will never quite yield the mirror-like shine you can achieve by burnishing with a stone. The term terra sigillata, which means ‘sealed earth’, Which method of burnishing you choose will depend comes from the name of a type of Roman pottery mass- on the clay you are using, the way you are firing and your produced around the first century AD. This pottery was level of patience. The form you are trying to burnish may decorated with impressed or stamped decoration, which also dictate which method you can use – a smooth surface is what the word ‘sigillata’ refers to. (Think of the kind of with no folds or creases, and no impressed, incised or stamp, or ‘seal’, which would have been used to seal wax sculpted details is ideal for burnishing with a stone. If on a paper document.) These pots were coated with the your form has a textured surface, or corners and curves same kind of very fine slip which Greek potters had been which a stone cannot get into, then you probably need to using for hundreds of years to create their famous black use terra sigillata. and red pottery. Though many books incorrectly refer to

www.ceramicartsdaily.org | Copyright © 2010, Ceramic Publications Company | Three Great Pottery Decorating Techniques | 8 Step 1: Weigh out Darvan Step 2: Weigh out the Stripes become notice- After settling (in this case, 7 or 811 and add it to the dry clay, add it to the able down the sides of the approximately 3 hours, but measured amount of water. water solution, and container as the heavier could be as long as sev- Helpful hint: If you always mix thoroughly. particles begin to settle. eral days), siphon off the mix your terra sigillata in middle layer of liquid from the same container, place above the layer of sludge. a permanent water-line on Be careful not to get any the side of the container so of the settled sludge in you don’t have to measure your siphon. the water every time.

this slip as a ‘glaze’, it was not actually a glaze but the Not all clays are equally suitable to make terra sig, and material we now call terra sigillata. the proportions of water to clay to deflocculant will be different depending on what clay you use. It is a ques- Making terra sigillata tion of experimenting with different types until you find Terra sigillata, or ‘terra sig’ for short, is made by mixing something suitable. You can try substituting any dry clay, a suitable clay with water and a deflocculant and leaving including scraps from your clay body, for the clays called it to stand until the heavier particles of clay settle out. for in the recipes which follow. The process is simple, but (Deflocculant weakens the electrical attraction between a bit time-consuming. First, measure your water, and stir particles of clay, thus breaking up small clumps of clay in the deflocculant. Weigh out your clay and add it to the and allowing the individual particles to float freely.) The water. For best results, be sure to weigh these materials deflocculant causes the finer particles to float in the wa- precisely. If you have a ball mill, you can ball mill the ter, which can then be decanted for use. In general it is mixture, otherwise, shake or stir it vigorously. Then place not possible to buy terra sigillata, so if you want to use the jar, loosely covered, somewhere where it won’t be it, you must make your own. disturbed for several hours to several days, depending on To make terra sigillata, you will need a clear glass or the recipe. plastic jar with a wide mouth, an accurate gram scale and After the appropriate settling period, you will see a a length of clear plastic tubing for siphoning. The only layer of dark sludge on the bottom of your jar, and if it ingredients are water, dry clay and deflocculant. Many has been a long settling period you may see clear (or pos- kinds and colors of clay can be used, including ball clay, sibly dark-colored) water on the top (this varies depend- kaolin, local clay or scraps of whatever clay body you ing on the type of clay and length of settling). It’s the part usually work with. There are also many possible defloc- in the middle – hopefully, about half the mixture – which culants, the most commonly used being sodium silicate, you need. Use a syringe to remove carefully as much of soda ash, Darvan 7 and Darvan 811. You might find the water from the top as you can without taking any of recipes calling for Calgon water softener, but don’t try the fine clay particles along. When clay starts getting into those – unfortunately Calgon doesn’t work since it was your syringe, it’s time to siphon off the middle layer into reformulated to eliminate phosphates. Lye can also be a clean container, using the clear plastic tubing – or for used as a deflocculant, and I have even experimented with a small batch, simply use the syringe. Don’t be greedy. using the waste water from washing wood ash. If you get some of the heavy sludge into your terra sig,

www.ceramicartsdaily.org | Copyright © 2010, Ceramic Publications Company | Three Great Pottery Decorating Techniques | 9 Center a pot on the wheel Once you have applied Turn the pot right-side up Using the polishing mate- upside-down, and while enough terra sigillata to and finish coating it with rial of your choice-a car- the wheel spins begin the lower portion of the terra sigillata. Apply just polishing mitt works well brushing on the terra sigil- pot, and it has soaked in inside the lip; there is no -bring the entire surface to lata from the foot. Apply so it is not glossy wet, use need to coat the entire a high sheen. two or three coats, until your fingertips to begin inside of the pot. you cannot see the under- polishing the surface as lying clay color clearly. you continue coating the pot with the other hand. it may never settle back out and you’ll have gritty terra Terra sigillata should be applied to a bone-dry or sigillata which won’t shine up as well. It’s a good idea almost bone-dry pot. If you are brushing it on, you need when you get close to the layer of sludge to switch to a to apply at least three coats. If you are putting white terra new container, so if some of the sludge gets in you don’t sigillata on white clay, three coats is probably plenty. The contaminate the whole batch. You now have a batch of terra sigillata needs to soak into the clay, but should not rather thin terra sigillata (along with a lot of sludge which be allowed to dry completely between coats. Once you can be discarded or used for some other purpose). It can have applied several coats, the surface should be buffed be used as is, or allowed to settle and evaporate for a few with your fingers, a cloth or chamois-leather before it days before using. dries completely. The pot is ready to buff when the surface looks waxy and grey but is no longer wet-looking. Applying terra sigillata If it has lightened in color, it has dried too much and Terra sigillata can be applied in two ways, by brushing another coat of terra sigillata must be applied. For the or spraying. Brushing is easier, but may leave notice- greatest degree of sheen, apply three thin coats and able brush-marks. On the other hand, spraying requires buff after each coat. more equipment, and may leave a bit of a pebbly texture Watch out for two things when you are brushing on where the droplets land on the pot. terra sigillata: don’t let it drip down your pot, because Before you apply terra sigillata, your pot must be the drips will show; and don’t allow your brush to lose smooth and dust-free. Terra sigillata is so fine that even hairs, as the hairs will make a permanent mark. Be sure if you cover a textured surface with several coats, the to use a good quality soft brush – a watercolor mop texture still shows. This is wonderful if you have a delib- brush works well. If you are brushing terra sigillata erately textured surface, and in fact, the only way to bur- onto a wheel-thrown pot, the simplest way to apply a nish a textured surface is with terra sig. However, if you nice even coat is to put the pot on the wheel and let the have sanded the pot, the surface is likely to be covered wheel do the work for you while you move the brush with little scratches from the sandpaper, which will not be up and down. Once you have enough coats on part of covered up by the terra sig. Even more important, if you the pot, you can start burnishing with the fingertips of have sanded your pot, you must carefully sponge off any one hand while you are still brushing the terra sigil- dust. Dust will cause the terra sigillata to peel off after lata onto another part of the pot with the other hand. firing. Therefore, if you want to achieve a really smooth If you have a large pot you are almost required to do burnished surface using terra sig, it is most effective to this to get a really good polish, or the terra sigillata apply it to a wheel-thrown pot which has been ribbed may dry out too much before you finish brushing it on. smooth after throwing or trimming, or if handbuilding, to Don’t touch the surface until it has soaked in, though smooth the entire surface at leather-hard stage with a rib. if the terra sigillata comes off on your fingers, it isn’t

White Terra Sigillata liquid into a large clear container, discarding the sludge on the bottom of the original container . 3 .7 pints (2 .1 kg) water • Let it settle for another 20 hours, then siphon 2 .2 lb (1 kg) OM4 Ball Clay the thin liquid from above the layer of sludge . 25 g Darvan 7 or Darvan 811 As soon as you notice the liquid getting a little thicker, stop siphoning and discard the rest of Red Terra Sigillata the liquid along with the sludge . 3 .9 pints (2 .2 kg) water 2 .2 lb (1 kg) Newman Red Clay 30 g Darvan 7 or 811 Jan Lee’s recipes • Measure water into a large glass or clear plastic Ball Clay Terra Sigillata jar with a wide mouth . 28 lb or 3½ gallons (16 liters) water • Add Darvan and stir. Add clay and shake vigor- 14 lb (6 .35 kg) Ball Clay ously . Leave undisturbed to settle for three hours . 3½ tablespoons Sodium Silicate • You will see a dark layer of sludge at the bottom of the container . Siphon off the liquid • Let settle 48 hours before decanting. portion above the layer of sludge . Be careful you don’t pick up any of the sludge . Discard the bot- Orange Terra Sigillata tom layer of sludge . 14 lb (6 .35 kg) Dry Clay (Orangestone • Try the terra sigillata on a dry test tile. If it from Highwater Clays) doesn’t give an adequate shine or still feels gritty 28 lb or 3½ gallons (16 liters) water when you rub it with your fingers, let it sit for 3 tablespoons Sodium Silicate another 12–24 hours, siphon again and discard • Let settle 6-7 hours before decanting. Allow the new sludge . One sign that you have a bad to evaporate to a specific gravity of 1 15. . Jan batch of terra sigillata is if it soaks in and dries Lee also sometimes adds crocus martis (a form very quickly . of iron oxide) to white terra sigillata to make a • If there are dark specks in the terra sigillata, put purplish color . She uses ½ teaspoon per cup of it through a 200-mesh sieve . Even if there aren’t terra sigillata . dark specks it won’t hurt to screen it anyway . It should be about the right consistency to use Some of these recipes suggest check- right away (a specific gravity of 1 .15) but if you ing specific gravity with a hydrometer. want it thicker, let it evaporate for a day or two . You can also pour 3½ fl oz (100 ml) of • Apply two or three coats to bone-dry ware, allow to dry just until the surface isn’t wet, terra sigillata into a graduated cylinder and burnish with fingers, a soft cloth, nylon and weigh it – if it weighs 115 grams stocking, chamois-leather, car-polishing mitt or it has a specific gravity of 1.15. This is a plastic bag . Don’t touch the wet surface and the recommended consistency for terra make sure your polishing cloth is very clean . sigillata. If it is much thinner it is hard For the greatest shine, apply three thin coats, polishing between coats . to apply enough without over-saturat- • For colors, add oxides or stains after settling. ing your pot with water. If it is much If you add too much, the terra sigillata won’t thicker, it may peel off after firing. In burnish as well because these materials have a practice you will get to know just how larger particle size than terra sigillata . you like your terra sigillata and you Charles and Linda won’t have to check the specific gravity Riggs’ Recipe of every batch you make. 28 lb or 3½ gallons (16 liters) water For more information about making 15 lb (6 .8 kg) XX Saggar Clay terra sigillata, especially if you want or OM4 Ball Clay to try clays other than those called 1½ tablespoons Sodium Silicate for in these recipes, I would highly 1½ tablespoons Soda Ash recommend consulting a comprehen- • Place the water in a 5 gallon pail and add soda ash and sodium silicate . sive book from the European Ceramic • Stir in clay—if you have a hydrometer, only add Work Centre called The Ceramic Pro- enough clay to get a specific gravity of 1 .15 . cess: A Manual and Source of Inspira- • Let it settle for 10 minutes then pour off the tion for Ceramic Art and Design.

www.ceramicartsdaily.org | Copyright © 2010, Ceramic Publications Company | Three Great Pottery Decorating Techniques | 11 Saggar-fired Orb by Charles and Linda Riggs, 2003. 9 in. (23 cm) in width. White stoneware sprayed with white terra sigillata, polished with a soft cloth, bisque fired to cone 010, saggar-fired in a raku kiln with wood shavings, steel wool, copper, and salt.

Naked Raku Orb by Charles and Linda Riggs, 2003. 7 in. (18 cm) in width. Stoneware painted with white terra sigillata and polished with a soft cloth, bisque fired to cone 010, covered in resist slip and glaze. Sgraffito through glaze before raku firing to 1400ºF (760°C).

ready to burnish yet, and you will mar the surface by is to make sure the terra sigillata is quite thin and watery. touching it. After you have applied enough terra sigil- It should take several coats to cover your pot, and the final lata to the whole pot, and there are no wet patches, depth of applied terra sigillata should be a fraction of a then you can start using a chamois-leather or a soft millimeter. The pot must be dry but not dusty. If necessary, cloth, or even a thin plastic shopping bag, to bring the use a damp sponge to remove dust from the surface before surface to a high gloss. applying terra sigillata. However, beware of sponging the If you are applying terra sigillata to a handbuilt or surface of your pot too much: every time you rub it with a sculptural piece, you may find it impossible to use the wet sponge you are removing particles of plastic clay and wheel to help with the job. In that case, you can still leaving behind the heavier particles of clay and coarse grog, brush it on, but be careful not to touch any wet spots. which don’t hold on to terra sigillata as well. After coat- You may also want to experiment with pouring, or even ing your pot, allow it to dry completely before firing; it is a dipping if you have a large enough batch of terra sigillata good idea to wait 24 hours. and a way to safely hold a delicate piece of greenware. Avoid a too-rapid increase in temperature during any firing – a pot which comes out of a bisque firing perfectly Troubleshooting smooth may peel in a hot and fast pit-firing. If you experi- Terra sigillata occasionally suffers from problems adher- ence a great deal of peeling despite following all these ing to the clay it is applied to. Terra sigillata is not integral rules, you may have to change the clay you use or the to the material the pot is made from, as is the surface of a terra sigillata recipe. One last thing to try is adding a little stone-burnished pot; at the same time it doesn’t adhere by CMC gum to your terra sigillata. This is a gum which is melting like a glaze does. Some potters prefer to burnish often used as a binder. It comes as a powder which has to with a stone for this reason, but you can keep this problem be dissolved in hot water before it can be added to your under control by attention to some rules of thumb in ap- terra sigillata. Add only a very small amount at a time plying terra sigillata and firing your ware. Most important and test as you go. CMC may reduce the level of sheen

www.ceramicartsdaily.org | Copyright © 2010, Ceramic Publications Company | Three Great Pottery Decorating Techniques | 12 Eagle Vase by Sumi von Dassow, 2008. 9 in. (23 cm) in height. Coil built from red stoneware (Navajo Wheel Clay from Industrial Minerals Co.), burnished with a stone, decoration with terra sigillata, and smoke- fired. Photo by Sumi von Dassow.

you get from your terra sigillata, and it will slow the way you can have a multi-colored burnished pot with a drying time. high level of sheen. I frequently use terra sigillata made Many potters use terra sigillata as a canvas for the from Cedar Heights Redart clay to paint intricate pat- fire to paint on, either pit firing or saggar firing their terns of fine lines on burnished pots made from red clay. burnished pots. However, other potters like the satiny I then smoke-fire these pots to achieve a black-on-black surface of terra sigillata as is, without any special firing. effect. I adopted this process because I found that plain Ricky Maldonado is a potter who uses terra sigillata clay slip often rubs off a burnished surface, while the as a base for painting intricate patterns, rendering them process of buffing terra sigillata to shine it up seats it with tiny dots of low-fire glaze covering the burnished even on an already burnished surface. surface of his pots. You can also try using terra sigillata to partially cover a surface which has been burnished with a stone. In this

Detail of one of Lana Wilson’s richly textured platters.

ana Wilson’s career spans a nurse, a kiln builder or a cook, more than 40 years and and when people open up about includes a vast repertoire those things, I learn so much,” Lof pieces and surface con- she said. “And, if I come across siderations, which she regularly something in ceramics that I don’t shares with students. She teaches, know about, I’ll ask the audience, on average, a workshop a month, and more times than not, I’ll learn and loves to do so. “It’s so easy, the answer.” really. The people are always inter- Lana worked with functional esting; you are instantly submerged stoneware for the first seventeen in a milieu of like-minded people. years of her life in ceramics. And I love the humor, and people are then, a job at a community col- so kind.” lege caught her eye, so, at age 43, What Lana really appreciates she went back to school to get her about teaching workshops is how master’s degree. For Lana, gradu- much diverse experience there is ate school completely changed the in the audience. “At any given course of her work. “Number one, time, your audience might include it opened up the way to lots of ex-

www.ceramicartsdaily.org | Copyright © 2010, Ceramic Publications Company | Three Great Pottery Decorating Techniques | 14 1 2 3 Smooth out a slab, layer, and press Use hand tools, stamps, and found Roll over the texture with a roll- in objects then texture the surface. objects to embellish the slab. ing pin, to soften and tuck in the marks.

4 5 6 Use a handmade viewfinder to Cut out a dart then use it as a pat- Lift and connect the edges where select an interesting area. tern to cut the remaining darts. the darts have been removed.

ploring and experimenting, which the slab on top of it. This netting has never ended,” she said. “Num- forms the basis of the texture com- ber two, I started making non-func- position on the back of the piece, tional work and using the electric though Lana will embellish it more kiln exclusively, neither of which at later stages. After smoothing I’d ever done before.” Now, Lana’s the front of the slab with a small focus has returned to functional squeegee, Lana uses a wooden roll- pieces. She told me one reason: “I ing pin from a pastry store to lay want my grandchildren to eat off of down some waffle texture, which things that I have made.” created impressed squares, then in Texture Throughout an adjacent area, she lay down and Lana applies texture in layers, rolled over plastic sink mats that and does so throughout her mak- left larger, high-relief squares (fig- ing process. During my visit, she ure 1). I watched her then target made a serving platter to demon- and go after some of the high relief strate how she works. squares with her small hand-held After using a slab roller to make stamps, and some found objects, a large slab, she lays out some inverting them with embellishment fruit netting on the table, and sets (figure ).2

www.ceramicartsdaily.org | Copyright © 2010, Ceramic Publications Company | Three Great Pottery Decorating Techniques | 15 7 8 9 Prop the piece up, level the sides, For handles, shape cones from large Lift and drop the cone two or three and adjust as needed. triangles cut from a textured slab. times to get an organic shape.

10 11 12 Slip and score the handle in place, Turn piece over on foam supports, Make a foot from a long, thin piece then support it with foam. fill seams and adorn the repair. cut from a textured slab.

I was surprised when she picked preliminary and secondary texture up her rolling pin and rolled over with a rolling pin, Lana embel- the work she had just done (figure lished further with one of her new 3), but she explained to me, “You favorite items, the red scrubby see, this softens it and makes it applicator from a Shout bottle, more interesting. I don’t want it and an old favorite, a seamstress’ to look like plastic surgery. I don’t marking tool. like the whole Southern California Forming the Platter glitzy sequin scene, I like old, worn Lana had created a slab much friends. I like layers; I walk regu- larger than what she actually larly in the Torrey Pines State Re- needed for the piece she had in serve when I’m home in San Diego. mind. She cut a framing device I love those layers of information out of a piece of paper roughly around me.” the proportions of her intended I looked, and the effect she had serving dish (figure 4). She used created by rolling over existing this viewfinder to locate the best texture was to ‘tuck in’ all the little part of her texture drawing, marks she had made, like treasures marked the boundaries by laying in lockets. After tucking in her down a straight edge then, using

www.ceramicartsdaily.org | Copyright © 2010, Ceramic Publications Company | Three Great Pottery Decorating Techniques | 16 13 14 Smooth the foot with a roller and cut Use a pony roller to bevel and finish decorative arches through it. both sides of the platter’s edge.

the straight edge again, cut out of the serving dish which allows the shape. them to firm up while supported. Lana needed to take two darts She fills in gaps in the texture out of each end to have the flat where the darts were removed shape rise up into the form she with paper clay to prevent cracks wanted. “Oh, I suppose I should from forming along the seam. use a template, but I never do,” To address the sides, Lana she quipped, knowing that I am grabbed a couple of paint stir- a template fiend. “I can never ring sticks, which she used to lift find the one I need when I need the sides and then shoved pieces it, besides, I know what shape I of foam beneath to hold them in need to cut out, and after I cut the place. She filled in gaps that had first one, I’ll use it to cut the other been made by cutting through three,“ she explained, as she cut existing texture on the edges, and out and removed the first dart. then compressed and beveled those She took the triangular piece of edges with a pony roller. Then, she clay she removed, turned it over, used a spirit level to make sure the and set it gently down to trace it edges, were, um, level (figure 7). “I where she wanted the second dart. don’t know a gallery who would She then took those two cut-out take a piece that’s not level,” she and placed them on the other end, murmured as she made slight ad- and traced and cut out the remain- justments. “There we go!” ing two darts (figure ).5 The size of the dart determines the shape Making Handles of the final form. After slipping The next task was to make the and scoring, she simply lifted and handles. First, she textures a slab butted the joining edges together and cuts out large triangles, then (figure 6), and then used small she rolls them into a cone (figure pieces of foam to prop up the ends 8), seals them using a pony roller,

www.ceramicartsdaily.org | Copyright © 2010, Ceramic Publications Company | Three Great Pottery Decorating Techniques | 17 and drops them on her work- the appropriate height, textured bench (figure 9). They magically the slab, and used a straight edge gain character with each whump. to cut a long strip of clay for Once she is satisfied with the the foot. She picked up the long result, she cuts away excess clay strip in loose folds and dropped with a fettling knife, scores and it a few times on the table. “This slips the end of the serving dish, makes an undulating line I just as well as the inside of a handle, love,” she told me as she worked. and then attaches it, stacking She placed the foot on the bot- foam beneath it for support (fig- tom of the pot, shaped it how she ure 10). wanted it, and cut the excess away, Lana constantly manipulates then joined the foot into a ring. Af- the surface of her pieces as she ter scoring and slipping the areas is making, adding texture as she that need to be joined, she at- goes. After attaching the handles, tached the foot ring to the bottom she grabbed a wooden dowel with of the serving dish and used a dry sharpened ends (a pencil would soft brush to remove excess slip work, too) to both re-draw and and blend the seam (figure 12). She enhance existing lines. After the then used a common loop tool to piece had dried to leather hard, she create a little looped arch on each removed the bolsters and turned side of the foot (figure 13). She it over on a large piece of foam rolled the edge with a pony roller, to access the bottom. She filled used a ware board to flip the piece the gaps in the seams with paper right side up, and used the spirit clay, again to strengthen them and level again to make adjustments prevent cracking (figure 11). When (figure 14). she makes a repair like this, she Lana has a delightfully free, di- adorns it. “I could teach a whole rect, and easy way of making, but course on cheating,” she joked, don’t let that fool you into think- while rolling a seamstress’ marking she doesn’t take her time in ing tool over the filled-in seam. the studio seriously. “I’ve changed my style of work about six times Adding a Foot through out my career., and each The last part of the serving dish time it takes me about six months project was to make and attach to a year to figure it out,” she a foot. Before she had turned told me. “People don’t realize the piece over, she had taken an that being an artist is really about approximate measurement with daily discipline; when I’m work- a seamstress’ measuring tape, ing, I want my time to work. I’m and had created a long slab to not one of those ladies who does texture. She played around a bit lunch. Ceramics is far too expan- with some scrap clay to determine sive for that.”

www.ceramicartsdaily.org | Copyright © 2010, Ceramic Publications Company | Three Great Pottery Decorating Techniques | 18 Finishing Lana Wilson’s work is mostly black cone 5, though she fires it to cone 6. and white with bits of vibrant color This clay body is half porcelain and splashed about. She says, “I have a half white stoneware. It’s not as white background in painting, and this tech- as porcelain, but it does fire white nique really appeals to the painter in rather than yellow in oxidation, isn’t CAUTION me.” She gleaned this current surface as finicky as porcelain, and works You must wear a respi- treatment from two artists, Denise well with Lana’s making methods. rator during this stage. Smith of Ann Arbor, Michigan, and If you’re buying clay from the East In the final step, she Claudia Reese, a potter from Texas. Coast, she suggests a clay body called dips the piece in a clear Little Loafers from Highwater Clays. glaze, and fires to cone Simple Slip 6. Through lots of ex- To prepare the slip, Lana takes 100 Easy Application perimenting, and with grams of small pieces of bone dry clay The technique is simple. On a piece lots more to go, Lana and adds 10–50 grams of a stain. The of bisqueware, first brush on black finds that ending with a percentages of stains varies according slip or one of the base colors (figure dark color on top works to the intensity of color she is trying 1) then sponge it off, leaving slip in best for her. to achieve. the crevices (figure 2). Then, using The clay Lana uses is Half & Half colored slips dab on bits of color here from Laguna, formulated for firing at and there (figure 3). Remove some

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www.ceramicartsdaily.org | Copyright © 2010, Ceramic Publications Company | Three Great Pottery Decorating Techniques | 19 of that with steel wool (figure 4). “I can’t use water for this step or it will NOTE muddy the colors,” Lana explains. Stain or oxide-bear- Recipes ing slips applied to Recipes Base Coat or Wash Colors surfaces that come There are two groups of colored slips. 6600 Best Black...... 10 % into contact with The first group Lana uses for the 6339 Royal Blue...... 5-10 % food need to be cov- base coat that she washes off, leaving 6069 Dark Coral ...... 35 % ered with a food-safe color in all the recesses. The accent Accent Slips clear glaze. slips are more intense and removed 6129 Golden Ambrosia ...... 30 % with steel wool. All stains are Mason 6485 Titanium Yellow ...... 20 % stains except for 27496 Persimmon 6024 Orange...... 30 % Red, which is from Cerdec. Add the 6236 Chartreuse ...... 50 % 6027 Tangerine ...... 15 % stains and bone dry clay to water and 6211 Pea Green...... 50 % allow to sit for 30–60 minutes so it 6288 Turquoise ...... 50 % will mix easier. 6242 Bermuda...... 10 % 6069 Dark Coral ...... 35 % 6122 Cedar...... 25 % 6304 Violet ...... 60 % K5997 Cherry Red*...... 30 % 27496 Persimmon Red (Cerdec)*. . . .30 % * inclusion pigments

Kate the Younger Clear Glaze Cone 6 Ferro Frit 3195...... 70 % EPK Kaolin...... 8 Wollastonite...... 10 Silica ...... 12 100 % Add: Bentonite ...... 2 % From Richard Burkett . Use over colored slips . Shiny, resistant to crazing, cool slowly .

Texture and isolated areas of bright color make Lana Wil- son’s work really pop.