Bare Clay
AMAZE WITH NO GLAZE
De-glazing and resist glazing The nude pot – finished effectsv Use of colored stains to enhance texture; washes
Clay has a lot of silica (glass forming material) in it already, lots of texture and some degree of brown or rust color from minerals in the clay body, except porcelain and other white clay like B-Mix. A fired nude pot with little or no glaze can be very attractive and it can hold water. However, a food serving bowl or drinking vessel should be glazed on the inside for aesthetics, mouth feel and cleanliness. Sometimes a partly glazed piece, with a splash of glaze at the top, or a wax-resist design can be very attractive. Some of Joel Park’s large vases have a simple glaze flowing from the top to half way down. Patti Jones’ bowls have glazed leaves floating on an unglazed background. Sally Murchison has made many interesting figures and whistles with carved or pierced designs and no glaze at all. Inlaid designs with contrasting clay color or slip are handsome without glaze as made by Yoko Haar.
It is good to remember to practice good form. A good form looks good with or without glaze. Plants and flowers do not mind.
Sally Murchison taught us a neat “deglazing” method. Using a white clay body which has been carved then bisque fired, dip the whole piece in Miller White, leaving it in the glaze for a while, at least 15 minutes. Let the piece dry, then start taking the glaze all off by scraping with a wood tool, then wiping it off with a dry cloth or a sponge, leaving glaze in the recessed carved areas. Wear a mask for this step to avoid glaze dust. The glassy parts of the glaze will remain on the clay body to give it a barely visible sheen. The recessed carved parts will retain the glaze, but so will any nicks and other imperfections which have not been smoothed away or cleared of glaze. After high
firing, the piece will assume the appearance of cool stone or marble with the carved design enhanced by the remaining white glaze. The piece is actually glazed because a very thin film has entered into the porous surface of the clay body.
White clay with light glaze works well using this technique. This technique can be done with darker clays, too, but the use of darker glazes with dark clay is recommended. White glaze on dark clay reveals very small imperfections unless that is the desired effect. Dark glaze on white clay can look messy and uneven, unless a desgn patern requires accenting. The dark glaze on white leaves a shadow of itself after being wiped off.
Designs drawn with wax or with adhesive paper stencils on the pot resist the glaze effectively showing the contrast between glazed and unglazed areas.
Another non- glaze technique is to apply a colored stain diluted in water, called a wash, to the piece which is textured or carved. Wipe most of it off with a damp cloth leaving the stained outlines enhancing sculptured forms. Iron oxide gives an earthy brown look. Manganese oxide, black outlines. Chrome oxide provides a very sharp, strong green.
When chrome is applied in addition to iron oxide on dark clay, a bronzy antique effect can happen. Cobalt oxide gives a royal blue enhancement of the carvings or texture.
The most important place on the pot not to have glaze is the foot up to about one half inch from the bottom. Let the clay body show and lessen worry about runny glaze “feets” after firing which cement the piece to the kiln shelf besides looking ugly. Pots can be seen coming out of the kiln with glaze all the way to the bottom. This is 10% good luck, and 90% application by an experienced potter who knows how to select and apply glazes. PJH Nov 2010