The way I designed my press is so it can fit 12 spot colors on 1 screen. Some tiles use anywhere from 1 up to 10 colors. And some projects may take up to 99 tiles. So sometimes a bigger tile project can be upwards of 12 or 15 screens. That’s around 100 to 500 spot colors on average that need to be printed to complete the project.
The scary part is you have to wait until it comes out of the kiln to know if it worked just right. Going back to press or even screen can really take the wind out of the sails.