I’m always learning (or is it relearning?) … The more heavily grogged the clay is the less the shrinkage! That is that size of your piece doesn’t change that much after it has been fired. Some clays can shrink up to 20% after firing! I often feel cheated when that happens. ?
But on the other hand, remember that your decorating options are limited with grogged clay. For example, sgrafitto isn’t successful with grogged clay.
Take a look I found out the hard way….
The surface appears rough/uneven and the grog shows through the sgraffito!