Pour thickness will depend on the hardness of the rubber chosen. Because softer rubbers are more flexible, they’re more prone to tearing. Generally, the softer the rubber, the thicker your mold walls should be, and vice versa. For example, VFI-2123 is a 25 Shore A rubber and should be poured at a minimum of 1 inch thick. On the other hand, VFI-2180 is an 80 Shore A rubber and can be poured at a minimum of 3/8 of an inch thick. Check out VFI’s TDI specification sheet or any individual TDS for recommended pour thickness minimums.