Custom stamp is a special die pressed into a cover fabric at pressure and heat.
The quality of the stamp greatly depends on the design, size and fabric combination. Before you order please contact support if we can make it for you. In most cases we recommend overprint option which is very similar, easier to make (no need to order the die) just without the physical indentation.
We need an .cdr or .ai file which is converted to curves and flattened. If you can't do it on your own, we will be happy to help you out for a small fee.