Because there are variables beyond my control (clays, papers, water, mixing errors and etc) always pre test fire what you have before a big project. No guarantee can be offered that 'alternative" commercial paperclays now on the market will meet the all the performance advantages of my high performance trademark P'Clay® brand only available from licensed manufacturers/distributors.
I tried extreme shapes with porcelain at Bechyne in the Czech Republic where overfiring was the rule not the exception at the time. The clay emerged from the kiln frozen in themiddle of a meltdown above: "Twisted" and "Old Flames".
From testing the limit of porcelain paperclay for heat in the kiln, I gained understanding of how big clay "moves" independently in the kiln and how to control or stop the movement in advance before the firing..
This technique is explained in more detail in my newer books.
imagination with risky forms
1. A "slip cast p'slip/p'clay" duck is seamlessly "attached" with p'slip and p'clay to a slab built "set of legs" in sculptors p'clay at bone dry. Joing differnt p'clays is clays is ok.
To the right below a right a smaller terra cotta with majoilca glaze passed the " firing test" in kiln at Pottery Northwest in Seattle, with out deforming in fire.
Above Right: These sort of bigger hollow forms are really dicey to fire because of hot spots in the kiln. It's easy to overfire them and then they warp or slump a bit. Double thick walls than these are better.