Have you ever wanted to make a piece of pottery to a specific size, but you didn't take the shrinkage into account? Or perhaps you tried to, but you did it by guesswork?
Both scenarios can lead to a lot of frustration. Believe me, I know. But we are not helpless nor hopeless in the face of our clay's peculiarities. We can indeed know just how big to make things in order to have them the right size after firing.
Here is the answer: make your own shrinkage ruler. Or a set of them, if you use different clay bodies. Yes, you can buy shrinkage rulers (aka shrink rules), but they may very well not be available in the percentage you really need. Plus, there is the satisfaction of making this tool for yourself. It really isn't all that hard!
Have you ever had a piece that shrunk in a way that caused you grief? Do you think a shrinkage ruler would have helped? Tell me about it!