I found some information on Pyrex Love that I found really helpful, and I just thought I would share it. First, the stamp on the bottom is simpler and has no number on it. I’m getting pickier about the Pyrex pieces I buy just because there are so many out there in poor quality, and they don’t sell for much.The primary color set of mixing bowls was first produced in the 1940s. I only buy them if they have no chips or cracks (a few scratches are OK), the patterns are in good shape, the patterns are fairly attractive to me, and they don’t show any signs of having been put in the dishwasher.
Later, in coordinating colors and decoration, they were a typical part of standard pattern collections, as well as in limited patterns and promotionals like chip & dip sets.
Respectively, they held 1 quart, 1-1/2 quarts, 2 quarts, 3 quarts, and 8 ounces.