Starting a personalized chocolate business.

Hi all

I'm thinking of starting a business from my office by customizing chocolates. The ones I refer to are the small squares that are used in weddings in hotels or other special occasions that come in a variety of colors of wrappers and have different written messages. I have attached a photo of the ones I am referring to and, by the way, I am in the United Kingdom. The problem is that it seems that I can not figure out how they print. Do you need a special machine or printer for that? I know there are ways to do it at home, but that does not seem professional. Any help will be appreciated, thanks