GA 23 with 3% copper carbonate, a dot of Blue Midnight ( clear with Mason stain cobalt)
clear transparent formulated to fit on porcelain (no crazing)
interior is same clear with 3% Burnt Umber
ClayPlanet's Icelia Porcelain and Laguna's Frost Porcelain
left: brushed on Rusty Bronze, inside Robin Egg Blue (Chun base wt Mason Stain)
right: thin dip into Rusty Bronze outside only, dried then full dipped into Robin Blue
light rutile spray on rim
All cone 6.
Over the last three months I tested different clay bodies and base glazes. I still use GA-23, Leitson's Chun, 20 x 5 Clear (Tony Hansen) with different colorants. I also found a very clear, craze-free glaze that fits porcelain nicely. I made up 4,000 grams of it to dip my little sgraffito cups. All glazes I keep at 1:3-1:4 density. The clear I dip for the count of "one-one thousand." The others at 3 seconds. The GA-23 runs if it touches any gloss glaze. It can be tricky, but when it works it is sweet. Lovely opal runs, but be aware. It also likes beige stoneware better than iron rich clay.
I found that although I like how lovely Laguna's Frost feels and looks, it is just too unpredictable. It looks very fancy with its translucent body and wily, talc-y ways. It teases and cheats with s-cracks no matter how careful you compress it with loving attention. Icelia by ClayPlanet, on the other hand, is a bit gray (kind of like me) and groggy (again, like me.) It is not sensitive or tender. There are no surprises---no light shines through---but it is strong and reliable. Nothing magical. That's left to the glazes, the kiln and clumsy me ;)
Now for a very fuzzy video: