They are tubes of hard chocolate and come in many colors.

Its very easy. The directions are: Place tube in hot (not boiling) water to melt. Turn and knead while heating to assure total melting. It took less then 10 minutes to activate the Candy Writers. I used metal tongs to grab the tube from the hot water and knead the chocolate. They are the coolest. I used them for the eyes on the chicks and I can't wait to experiment with more colors.