I have the 8 qt Ultra Instant Pot and make Yogurt. My first batch I used 8 oz Mason/Ball Jars. However, I share/give this to friends and don't get the same jars back. EEEEK. I need my canning jars and do not always want to buy more. So I bought 2 sets of these in the 8 oz. I made a big batch of Yogurt last night intending to use these containers. Tried a Sharpie on the lids first, then tried to get it off. Oh no that was not easy at first. Dawn and dishcloth didn't work well but lightened the writing. I used my homemade soap neat with just my finger, and took it all off left no remaining marks. So that was GREAT. Filled these cups up to the 6 oz mark, and actually my Batch of Yogurt needs another 6 containers...LOL These are really great for what I needed, and stack nicely in the fridge. Oh by the way.....MADE IN FRANCE.....NOT CHINA.