Family tests on Matte 11 and Glossy 17

I'm lucky that I found two glazes that I liked on the first try, so I did a couple of color tests on the .7 Limestone glaze sets.  My porcelain is still drying on the bats, so I only had tiles made from white stoneware (Dan's Four Equal Parts) and class clay.  I ran tests on #11 and #17 from the first grid, using .5% and 1% FeO.  I chose black iron oxide because it was very late, I was tired, and I confused the information about black iron with that of black cobalt oxide.  It was a fortuitous mistake, as I really like the color it produced.  It's a beautiful pure blue, at least in the .5% range:

The .7 Limestone set with .5% black iron oxide (FeO) on
white stoneware.

 

.7 Limestone set with .5% FeO on regular stoneware.

I love the way the glaze pools in the design, especially in the #12 and #18 slots.  I think I'm going to use those instead of #11 and #17.

The 1% tiles, on the other hand, are a monument to poor testing practices.  I filled my glaze syringe with 40 ml of a 1% FeO solution and put 2 ml in each cup of glaze, working backward from Cup 35 to Cup 16.  Those were the closest to me, and I was afraid I would knock them over if I reached over them to Cup 1, so I worked backwards.

By the time I reached Cup 15, I had to refill the syringe.  As you can see from the fired tiles, iron doesn't stay in suspension very long.  It settled out so quickly that the first cups received a stronger solution than subsequent ones. When I started with a fresh syringe, the first cups filled again received the highest concentration of iron.  That's why Row 3 and Row 7 have the darkest colors.

.7 Limestone set with 1% FeO on white stoneware

.7 Limestone set with 1% FeO on regular stoneware