I found these 4 cup measuring cups for a dollar a piece at the warehouse market grocery. They have a stamp of 5 PP on them and this is what it says for that.
<5>PP (polypropylene) has high tensile strength, making it ideal for use in caps and lids that have to hold tightly on to threaded openings. Because of its high melting point, polypropylene can be hot-filled with products designed to cool in bottles, including ketchup and syrup. It is also used for products that need to be incubated, such as yogurt.
They measure 4 7/8" across the top and 4 1/4" across the bottom (slightly tapered) and is 4 5/8" tall. They are smooth inside and out also have a small rounding at the bottom that would give the cheese a rounded edge rather than a sharp one. ( I hear corners dry out faster and rounded is better)
I have a question on drainage holes.. would drilling 1/8" holes 1" apart staggered be sufficient for drainage?