At The Chocolate Mold Factory main site, there are articles about using photopolymer plates to make custom chocolate molds with logos, text, and other computer graphics. In the same line of thinking, one can also use rubber stamps. The process of making rubber stamps is very similar to photopolymer plates. In fact, many rubber stamps are made of photopolymer, a chemical which is sensitive to UV light.
To use a rubber stamp to make a chocolate mold, you can take a finished rubber stamp and attach it to a base in the shape you want your chocolate. Say for example you wanted a bar. Well, you could take a plain chocolate bar mold and attach the rubber stamp to the top of it. Next, to make the mold you would pour food grade silicone rubber over the mounted stamp. When it has cured, remove the rubber stamp and base. Now you have a custom chocolate mold.
If you are going to be making chocolates for your own use, you can go to the craft store and buy rubber stamps. However, I wouldn't recommend doing this if you intend to sell the chocolate or the mold. The rubber stamp industry is very sensitive to copyright infringment. Check with the rubber stamp manufacturer's "angel policy". An angel policy is a rubber stamp company’s established permission for use of their images by the consumer or copyright use policy. Each company has its own policy. Some images, such as licensed images have different, usually more restrictive policies.
If you want to do logos or custom graphics, you can have a rubber stamp company make custom unmounted rubber stamps for you. One of the many companies that provides this service is Picture My Stamp. Their premium custom rubber stamps are made with natural gum rubber. The deeply etched image is twice as deep as regular stamps. You can email them your custom artwork and they will make rubber stamps for you. You can buy them unmounted and then just cut them to the size you want. You could also have them cut it for you.
Using rubber stamps to make custom chocolate molds in this way is generally a bit more expensive than using photopolymer plates or magenesium hot stamping dies. However; they are much easier to work with and there are more companies you can order them from. You may even be able to contact someone in your local area that can make the rubber stamps for you, which would save alot of money on shipping costs, not to mention that you would probably get it in a shorter period of time.