PB103 Iznik vase - experimenting with new and old underglazes at high temperatures

Item four in the Christmas firing was a small PB103 Iznik vase. I was experimenting with thin closed forms when I made the vase. It was reasonably pleasing to hold to I kept it and fired it to bisque. Once I purchased a new set of underglazes, it seemed like a good candidate to trial the colours at stoneware temperature. The following are the colours I had available. These are presented on a buff coloured tile so the PB103 expression is likely to be different.

L-R: R1. summer blue, electric blue, cobalt blue, turquoise, peacock, jade. R2. Redwood, Crimson, Saffron, Citris, Leaf, Brunswick. R3. 28A, Black oxide, Light Jade. R4. 28 original.

Not knowing how the colours would turn out, I selected Crimson, Turquoise and Cobalt blue for my design. I know blue is stable at high temperatures (see the Blue on White essays) so I figured those elements would probably remain. The temperature range on the crimson suggested it'd probably burn away so I used it for non-essential items. These were the small swirls at the base of the vase, the flower insides and the dots around the petals.

Close examination of the flowers show a very pale pick remains. I may use crimson in the future if I'm aiming for a pale pink as I'm told pink and purples are difficult to deliberately achieve. If I want a bright red, I think redwood may be the way to go. I'll have to make a PB103 tile and test the glazes on it to see. On the buff clay it seems to be more orange and less deep red than I expected. It will require a test though, because the buff clay contains something that reacts with the glaze, creating blushing near where some specific glazes are applied.