Summary

This is a mold to make a silicone cap for the very common #2 can. (Diameter around 74 mm.) I often have a half empty can of chili, soup or beans or whatever in the fridge and seal it with plastic wrap. This can cap is much better. I make these silicone lids for bowls and other containers. They are very easy to clean.

First off, this mold is deep. A 2-part PETG mold was a lot of trouble. Two parts was necessary to get the cap out of the mold.

So here I printed this one-piece mold with a stiff, but somewhat flexible TPU, hardness is 98A. It prints fast using PETG settings.. (Didn't try the common, softer 95A TPU but it should work too.) (UPDATE: Soft TPU works fine. Much easier to demold. The soft, 95A TPU was a long, slow print of around 3 hours)
Since the mold is slightly flexible, the cured silicone can be carefully removed. The little hang-tab is a good place to begin.

Update 1-18-26 I'm adding two smaller cap molds. A "#1" can, about 66mm in diameter, commonly used for tomato sauce, and one roughly 53mm Dia. used for tomato paste. Silicone volumes are near 9cc and 15cc. I would recommend the molds be printed in the flexible 95A TPU, for ease of release... End update

This silicone was a NicPro 30A. Fully cured and post cured at about 150F it is pretty tough and stretchy. I want to emphasize that demolding something like this requires some patience. The volume of one silicone cap is 24cc.

Note: The print needs support under it. Reduce the support "degrees" or "angle" to perhaps 5%. This will prevent support from appearing inside the mold, due to curvature of the upper edge. The rest is orca slicer defaults. (The Orca support Threshold Angle default is 30 degrees.)