INCISING - Clay.
ca: INCISIÓ - Argila
Incising is to engrave a design by cutting or scraping into the clay surface at any stage of drying, from soft to bone dry. With hard bone-dry clay you will obtain more precise lines, but you have to be very careful that it does not break. After incising, clean off the loose bits with a strong brush, then smooth the edges with a soft damp brush. Incising is useful for making textures.
Note: Incising becomes sprigging when it goes through the clay, leaving a hole.
Incising soft clay:
a) Using tools with pointed heads of different sizes you can free-handedly indent a design into the clay as shown in the above illustration.
b) To mark a design onto soft clay, first draw the design on thin paper, lay it on top of the clay and with a very thin piece of wood with a slightly rounded head, go over the design, slightly forcing it, so that it leaves the outlines indented into the clay. You can also pounce with a needle, going straight through the paper into the clay. Then, following the lines, incise your design into the clay.
Incising dry clay:
a) To mark your design onto dry clay, place a carbon paper on top of the clay, then your design on top of it and draw over the outline so it is marked onto the clay. Alternatively, pounce the design and mark it on to clay with coal dust or industrial talcum powder.
b) When the outlines are marked on, scratch and scrape off the parts needed for your design, brush off all the small bits of clay, then pass a damp, soft brush over it to smooth off the edges.
Decorating incising: The clay can be covered with transparent glaze, which when fired accentuates the incisions, or the incisions can be filled with glaze colors or colored clays. When full, the surface is then leveled out and cleaned using a flexible tool, like a kidney, so only the incisions have color.