Hi, I make instruments known as ocarinas. As for any instrument, ocarinas must be tuned. The smaller the chamber size, the higher pitched the instrument and vice versa. The problem with this is that as the clay shrinks during the drying and firing process, the pitch is significantly raised. I would like to reduce my shrinkage as much as possible to combat this issue. Iv'e read online where some people say mixing talc into your clay body will reduce shrinkage. Also I've seen where people suggest