There are many answers to this question! You can use a 9x9 inch pan. Or you can use a smaller 6x6 inch container (we often use those Pyrex containers at home...they come with the lid which makes it easy for storing when the dessert sets in the fridge). If you use a smaller container, you'll have to decide between making a "taller" agar agar dessert (because you're filling the container higher) or using multiple containers. You can potentially use one 6x6 inch container and then pour the extra liquid into two little glass cups to make mini/individual agar agar desserts (don't forget to add strawberries into those cups first). We do that a lot ^_^