Blacks
GLAZE OF THE WEEK 5
BLACK AS THE ACE OF SPADES HPG HAS THREE BLACKS G-Black: A glaze with two faces.
semi-matt, satin black finish
handsome with wax resist design on porcelain
stable, does not run, very reliable class glaze
good with accents of UH Blue, CR17 Red, Nelson’s
This is a very iron- rich Cone 10 glaze which also contains other minerals to make it as black as possible. It is a very stable glaze which never runs, and has a semi matte finish. It works well with any clay body, but it is especially good on porcelain or other white clay which has a smooth finish. On dark clay iron crystals may form.
Scraffito, scratching a design into this glaze, works very well. Using wax resist for a design then glazing with G-Black is an interesting technique. Sally Murchison taught us an excellent technique using this glaze on white clay body. Using adhesive tape cut to size, tape a multi-line design onto the bisque fired piece. For example, lines across the edge of a plate or random lines could be used. Then dip the piece in G-Black. After the glaze is almost dry on the pot, carefully peel off the tape, leaving unglazed areas. After firing, the taped design is white on black, very handsome.
A surprising feature of this glaze is that it has two faces. If Nelson’s Transparent is used as an accent trailed on top of G-Black, or if a G-Black design is brushed onto Nelson’s Transparent, the color will be bright royal blue. This is because there is cobalt in the formula. What does not work is to glaze a pot with G-Black, then superimpose Nelson’s Transparent. by dipping again. This is too thick, might run off the pot, and look plastic. Another non-workable technique is to dip a pot in G-Black then paint Nelson’s Transparent on. It will always look “painted” with brush strokes that one may not like, unless it is part of a design.
Other accents with G-Black are Miller White and UH Blue. These lighter glazes break into white-blue irridescence. CR 17 Red glaze as an accent can come out bright red on top of the black, but this is not reliable. Toshiko Orange can look like baked cheese, or if very well reduced sometimes on the inside of a bowl or plate, it can be very golden in appearance. Henderson’s Turquoise accents can be good.
CELADON BLACK
Kenny Kicklighter introduced this fine glaze to HPG from Pacific University. The finish is a very handsome metallic black due to ultra fine crystals in the surface.
It is still a new glaze therefore not many combinations have been made. Most likely this will be a stand-alone black glaze.
RACHEL’S BLACK
This glaze was introduced to HPG long ago about 2003. The first few batches were a semi gloss glaze the color of a ripe olive, with some green hints. It was beautiful with Miller White trail, or Henderson’s Turquoise. Then new batches became very shiny, like patent leather. This was used successfully for about a year when it ran out and new batches were made. These were very different, a semi matte black much like G-Black.. There is no explanation for this except that one of the components is a different batch from the supplier, or a different mesh size which might be critical for this glaze.
PJH April 25, 2005 4/14/07 ed. April 22, 2009 Nov 2010