|Monthly Tech-Tip |
Triaxial blend showing talc additions (left) and titanium additions (right).
Top tile: Pure Ravenscrag Slip (RCS)
Bottom left tile: 85% RCS, 15% Talc.
Bottom right tile: 95% RCS, 5% Titanium Dioxide.
Clearly, talc additions to RCS produce striking variegated silky matte surfaces (in 10-15% amounts). But the addition of a little titanium further improves the effect (especially on the second title in the bottom row: 88% RCS, 10% Talc, 2% Titanium. And the center one: 90% RCS, 10% Talc, 3.5% Titanium). But surprising are the two tiles on the bottom right: 90% RCS,10% Talc, 3.5% Titanium and 96.5 RCS, 3.5 % Titanium - They are glossy brown. This suggests that the MgO in the talc impedes the development of brown and the iron in the RCS is all the TiO2 needs to make a dark brown.
A super white powder used in ceramic glazes to variegate, opacify and moderate color.