Here are two photos of cups glazed with the same combination of Shinos. One cup was slow-cooled and the other was allowed to cool naturally. For the slow-cooled cup, the kiln was turned back on during the cooling process to hold the kiln temperature at around 1030C for approximately 5 hours. The other cup simply cooled at the natural speed of the kiln (which is rather fast, less than a day for it to cool completely).
The first cup with hues of brown, pink, red and metallic textures is the slow-cooled cup. The naturally cooled cup has quite clear red and white (red where the shino was applied thin and white where it is thick). Where the shino was applied thin, the slow-cooled cup is rather brown/red with a metallic sheen while the other cup shows a rather even reddish orange color. I believe that this difference is more due to the temperature hold having dropped at one point to around 980C, which I’ve noticed encourages a browner/metallic surface when shino is thin. If I really hold at around 1030C for the entire cooling process, then the thin shino also remains quite red (but I have yet to confirm this theory).
The most interesting differences appear where the shino is thick. On the slow cooled cup, we can see that iron was able to migrate* to the surface of the cup and create hues of pink/orange/brown with metallic luster (the metallic luster is hard to see in the photo). On the naturally cooled cup, the thick shino remains rather white and creamy (in the photo, the white is a little blown out, but it is still a rather creamy white).
*”migrate to the surface” is probably an incorrect term. Rather it would seem that when holding a glaze at a certain temperature, you give time for the metallic oxides already present to align in a structured way thus changing their crystallization (and color and texture). I’m still learning about what really happens on a chemical/physical level. Please send me message if you’d like to share information about what happens during a glaze’s cooling process!