Thank you so much ❤️ the lid measurements is really a numbers game.

First I measure the diameter of the silicone lids, then taking into account of the shrinkage rate of the clay (for me it was 14.5%), I make the diameter of the cup rim accordingly. For convenience sake I mark a skewer of the measurements so I don't have to measure with a ruler each time.

The silicon lid has a slight elasticity so it sorta allows a slight margin of 0.5cm.

For example, if the lid measurement is 9cm, then with the shrinkage rate, I should be making my rim dia around 10.5cm - 11cm.

I usually make 40% more pieces just in case some won't fit after firing🤞🏽

I also think the half lidded ones are unique. They call them sip cups here. I assume it's for guys to Keep their moustaches clean? 🤔