ok before your say craft or more "duckies and chickens" let me tell you about this.
Started as an exersize in clay shrinkage and designing to fit.
As we know, clays have different shrinkage numbers and temp certainly has an effect on that shrinkage.
The experiment started with just going by the shinkage numbers given with the clay body. I soon discovered that there is some deviation to that number (they should give the average shrinkage and an observed deviation). But I digress.
I liked the way they looked and they were different. So......
I measure the appropriate dimensions on the found glass objects, interesting things from thrift stores. I then throw a base and a lid, based on the glass dimension, plus the published shrinkage, plus a fudge factor that you have to determine with the clay you are using.
I bisque, the glaze, fire to cone 5 (stoneware). Usually now, I get a pretty good fit. Sometime the lid is a little big or small though. if I like the way the lid looks, I'll grind or add cork or foam filler.
I found that folk like and actually buy these. If you want more info, shoot me an emai.