I haven't posted anything for a couple of weeks and the reason is long long hours of rock crushing, grinding and volumetric blending - none of which are immediate enough to be photogenic or exciting enough to be written about. Still, due to popular demand (one comment) here is one of my Edinburgh biaxials.
Basically it is a way of testing glazes that gives far more insight than just mixing up an individual glaze. The basic glaze has two variables, one along each axiz, so that a sort of map is made up. The first 4 vertical rows on this tile are a 20 glaze biaxial based on a basalt rock. The two variables are calcium, which is increased from left to right, and silica, which is increased from top to bottom.
4 corner glazes are mixed up to a specific volume and the rest of the glazes are made up by volumetrically blending these glazes using syringes.
It's a long process and as you can see from this tile, rarely gives a final glaze - more an insight into how the materials are behaving. Most of these glazes are rather revolting brown sludges but there is a bit of promise around glaze 14, so this will be the starting point of the next.....Onwards and upwards.....