Surface Decoration. Design techniques used to put on the surface of the pottery. Slip Oxides Glaze Embossed Incised Wax on wet Altered from the wheel

Transcription

1 Surface Decoration Design techniques used to put on the surface of the pottery. Slip Oxides Glaze Embossed Incised Wax on wet Altered from the wheel

2 Slip

3 How to apply slip Colored slip is intended to add color to a pot by using the color of the slip and the color of the clay as well. The colors of the slip will turn their true color only after the glaze fire. The slip must be the texture of chocolate pudding or a heavy cream. Slip must be applied on wet to leather hard clay. If put on dry clay the wetness of the slip applied to bone dry clay could lead to cracking. Materials used to apply slip: Brushes brushes don t hold much slip, however if you want a brushed or painted look, or you are brushing over large areas of the pot, brushes will work. Slip trailers a bottle or syringe. These will hold larger amounts of slip and allow for smoother flowing lines.

4 How to apply slip Resist shapes RESIST SHAPES place the paper shape on the wet pot and smooth it over to release any trapped air. Pay particular attention to the edges of your shape. Sponge or brush a layer of colored slip onto your pot, be careful not to disturb the paper shape. Take the paper shapes off when the slip loses its wet, shiny, sheen. If you remove them too soon the design will smudge.

5 How to apply slip using stencils Patterns are cut from paper or contact paper. The patterns or designs are placed on the leather hard pot. The slip is then brushed over the stencil. The stencil is then peeled away to reveal the design.

6 How to apply slip with wax resist Brush liquid wax on the surface of your clay. Clay should be wet/leather hard. Create a design using the wax. When the design is complete gently brush the colored slip over the design. The wax will burn away in the bisque fire. The design left under the wax will retain the color of the clay.

7 How to apply slip painting it on Slip is directly painted on the leather hard pot using a brush. Slip should be applied with a fully-charged brush and in successive thin coats (as opposed to single-stroke built up-or thick- brush patterns). A thin application of slip may be partially dissolved if a transparent glaze is used over it. A very thick coating may crack or even peel off the pot, even though it appears perfect after application.

8 How to apply slip slip trailing Pour slip into a syringe or plastic squeeze bottle. The slip is then squeezed through the tube onto the surface of the clay. The clay should be leather hard. If the clay or the slip is too wet the line created by the trailing could bleed. If the slip is not a smooth runny texture (the consistency of cottage cheese) it could clog the tube and come out unevenly.

9 How to apply slip - sgraffito Sgraffito depends on the strong value contrast of the slip color to the color of the clay body. The slip is painted on the entire surface of the leather hard clay. When the slip dries (with in a few minutes) a sharp tool is used to scratch a design through the coating to the clay body beneath.

10 How to apply slip the opposite of sgraffito In the leather hard clay carve a pattern. The carving should be about 3 cm wide. Fill in the carved space or grooves with a slip trailer. Let the slip dry until it loses its shine. Then take a bendable metal rib and gently scrape away the raised surface of the slip. So the slip that remains will be flush with the level of the clay surface. As you scrape be careful not to pull the slip out of the grooves.

11 How to apply slip slip combing This requires patience and practice. The clay should be a flat form (plates, tiles.) The surface is to be flooded with the slip-hold the clay at an angle and pour the slip over it. Lines of a different color slip are then applied over the wet slip. While the lines are still wet and shiny a comb from which teeth have been removed (so every 3 rd or 4 th tooth remains) is drawn lightly through the lines across the surface. More complex patterns can be achieved by drawing the comb across a second time, parallel to the first but in the opposite direction.

12 Oxide

13 How to apply oxides APPLY OXIDES VERY, VERY THIN. Do not paint them on like glaze. Oxides can be brushed on textured surfaces and wiped with a sponge so the grooves retain the oxide. Oxides can be painted on thinly like a watercolor painting, then you may put a clear (Clear Bright NOT Clear Matt) glaze over them using a sponge.

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18 Glaze

19 How to apply glaze The glaze should be thoroughly mixed before using. The consistency should be that of a heavy cream. Rinse your bisque piece under water to get the dust from the kiln off. This dust can create little bubbles in the final firing on the surface of your pot if not removed. Glaze can be applied by: Brushing (apply two coats) Dipping or Pouring (dip once and do it QUICK)

20 How to apply glaze - Brushing Brushing the glaze on tends to be slightly thicker. There is more gum in the glaze to help it stick to the pot. Be careful not to trap small pockets of air under heavy layers of glaze. These can cause little pin prick holes in the fired glaze. When glazing a pattern you can draw the pattern on with pencil. Draw soft lines, these lines will disappear during the firings. When glazing these patterns be careful not overlap the edges. Treat the glazes like crayons in a coloring book. Glaze up to the line leaving a small needle tool thin line in between the glazes. This line will help the glazes not bleed into each other. You can also draw or carve the pattern into the wet clay and then after it is bisque fired you can glaze in the pattern you ve carved. To get a clean line of glaze around patterns: Thin the glaze down, use a watercolor brush, apply 3 coats, and use a steady hand.

21 Brushing glaze

22 How to apply glaze - Dipping Dipping will give the outside a more even coat than pouring. Work QUICKLY! (if you don t the glaze will be too thick and will bubble and crack.) Wax the bottom of the pot. Carefully-once the wax is there it is there forever. Trying to scrape it away doesn t work. Hold the tip of your pot at an angle. Dip the pot into the glaze QUICKLY. Swirl the pot around and pull it out QUICKLY, holding the pot upside down so the glaze will flow to the top of the pot. (if you hold it so the glaze drips to the bottom the glaze will melt and stick your pot to the kiln shelf.) Wipe the glaze off the bottom with a wet sponge. Take a tool and scrape a straight line around the bottom edge. If needed scrape a thin layer of glaze off the thickness at the bottom so it wont pool and stick the shelf in the firing.

23 Dipping in glaze

24 How to apply glaze Pouring You will need a generous amount of glaze. Work QUICKLY! (if you don t the glaze will be too thick and will bubble and crack.) Pour the inside of the pot only half way. As you pour the glaze out roll the pot around to cover the uncovered areas inside the pot. To cover the outside of pots place them on sticks upside down over a bowl. Having waxed the bottom of your pot, pour the glaze over the outside of the pot.

25 Glazing with wax Wax will repel the glaze that is put over the top of it and will melt off during the firing. Paint a design with wax on bisque ware very carefully and deliberately. Can put wax directly on the bisque or glaze and place the wax on top of the glaze, then put a second coat of glaze over the top of the wax. Brush or dip glaze over the top of the wax. Gently scrape the beads of glaze off the top of the wax. Do not scrape off the wax. It could scrape off the glaze from under the wax, and the glaze underneath will have an uneven coat.

26 Wax - trouble shooting Once the wax is on bisque ware it is there to stay. Even if you scrape it off, the wax has still soaked into the clay and will repel anything that is put over the top of it. Only wax the bottom of your pot if you intend to dip it. You do not need to wax the bottom if you are brushing glaze on. Once the brushes are loaded with drying wax you will need to rinse them with hot water and soap. The wax will be applied with cleaner, smoother lines if there is not excess wax in the way.

27 Glazing trouble shooting If the bisqued pot is too wet (from rinsing or pouring the inside) the outside glaze may not take. The glaze will be too thin because the pot is wet. If the pot is too dry sometimes the glaze will be too thick. Work QUICKLY! (if you don t the glaze will be too thick and will bubble and crack.) When glazing patterns with more than two colors, be careful not overlap the edges. Treat the glazes like crayons in a coloring book. Glaze up to the line leaving a small needle tool thin line in between the glazes. This line will help the glazes not bleed into each other. To get a clean line of glaze around patterns: Thin the glaze down, use a watercolor brush, apply 3 coats, and use a steady hand.

28 Glaze over slip

29 Embossed

30 How to apply embossed pieces Embossing means to add pieces onto the surface of your pot. This is done by scoring and slipping. To create the design you may mold the piece by hand. (like the frogs) Or use a press mold to create the piece. (like the chicken) You can make your own press mold out of clay and plaster.

31 Molds for embossing To create a press mold. Make the design out of clay. Place in a container. Spray with a spray soap or slimy substance. Put wet plaster over the design. Let dry, then remove the clay. The plaster needs to be dry enough that when removing the clay it won t chip the design and wet enough that you can still remove the clay. You can also take a block of freshly poured plaster and carve a design into it. This is called a sprig.

32 Embossing trouble shooting When attaching the piece be careful to not damage the piece you are adding. Make sure there are no air bubbles trapped under the piece. If there are air bubbles the piece will blow off in the firing. Carefully take a modeling tool and push the outside edges into the surface of the pot. Clean around the edges with a modeling tool.

33 Incised

34 How to carve incised designs INCISING - Incised designs are made by scraping a tool point across the surface of moist or leather hard clay. When a solid tool is drawn across the surface the clay pushed aside forms burrs or little clay crumblies. Scrape these away and re-carve the line. Do this 2-4 times until the clay crumblies are gone and the carved lines are clean. If the tool is held at an angle the lines will look cleaner. CARVING Best done on clay that is leather hard. It can be done on bone dry clay but the resistance to the tool is greater and chipping is more likely to occur. PRESSING OR STAMPING Moist clay is best for using a stamp or found object to press into the clay creating a pattern. A single stamp can be used multiple times to create an overall pattern. Because the clay is soft the back side should be supported when pressing or stamping the clay. Stamps can be made from wood, plaster, bisqued fired clay, tools, nails, bolts, keys, screen wire, cloth, leaves, fingers etc.

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38 Altered from the wheel

39 How to alter from the wheel Altered from the wheel combines wheel thrown and hand building techniques. It is more than making a teapot-where a spout is score and slipped on. It is more than embossing-where a design is placed on the surface of the clay. It is more than carving-where a design is carved through the wall. Altered from the wheel is the whole piece. A piece is thrown on the wheel and the structure of the pot is changed by manipulating the clay with your hands The round rim of a pot can be squared using flat pieces of wood. The pot can be cut and bent. Almost peeled like a banana skin. Two wheel thrown pieces can be cut apart and scored and slipped together.

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41 Wax on wet Let wax dry. Wipe clay with a sponge. This will remove the clay that is not protected by the wax. Paint wax on leather hard clay. Your piece should already be trimmed. This process does leave the clay with a grainy texture.