A couple things about plates and platters. We always throw our plates on plaster bats. Especially with large platters it is impossible to pull the cutting wire straight across the bat without it arching in the middle so that when you go to trim you have a thinner middle to contend with. With the plaster the clay is just right for trimming and it is flat as a pancake. With large platters I have these thin bats with a hole in the middle that I plop on the platter as soon as it will hold it. This helps the middle dry out and keeps the rim from not only drying out and lifting up. I think in a pinch you could make these rings from the top of a pizza box for smaller plates.
Here is a pic of Sheila cutting the sides off the thrown plates to make them square. She gives a Surfoam to the top and bottom edge so that it has a nice profile. This is where a Peter Pugger would come in handy for all the leather hard cut offs.
It's Saturday and we serve Pino Grigio in the showroom. It's been awfully quiet around here which means we may drink all the wine. Well pitter, platter off to work I go!