BE suggests cutting the top layer (reactive ice) slightly larger than base. Strictly guesswork on my part but maybe it aids in stretching and breaking up the irid surface so the crackle can develop. I did not stick to this guideline due to the thin rim of irid peeking out on the bottom after firing. The top and base were cut flush. This could be a good design element by removing the thin layer of irid at the border before putting the piece together. The result would be a decorative border around the piece.

The next pieces are kiln-carved using 1/8th fiber paper under the entire piece. I thought that it would disrupt the irid enough to leave a distinct pattern but it did not. A nice little kiln-carving but certainly no different than using regular irid.

It matters ( a LOT) what part of the sheet the reactive ice irid is cut from. The irid is thinner or a different color. I think the sheet I was working from was a rainbow irid which would have silver irid on the other edges; or the iridizing was thinner.IceEdgeIrid

This is again turquoise 1116 or light turquoise 1416. The spiral shape on the left tray (at top) appears to have a darker design but is a trick of the light. There is light transmission through the darker areas but lying flat it appears a very dark russet brown.

An Attempt was made to kiln-carve using fiber paper cut into leaves with emerald green 1417. There was no reaction at all in spite of multiple firings. The refires were to try and correct signifcant trapped bubbles between base and irid, around the leaf shape. I surrendered after 3 tries.