MOLDLAY is perfect for the maker interested in creating their own molds with the help of a trusty 3D printer. There are two suggested methods to achieve the molds you are looking for. One approach is to 3D print a negative of your object, then fill it with your resin of choice.
The other method is to print your object, then cast a mold from your print with concrete. The following video demonstrates this process completely.
MOLDLAY Specs and Qualities: