They have been designed so that the actual template itself fits inside the size square that it is. ie: a 10″ heart fits exactly to the edge of a 10″ square. If you wanted a heart that once quilted sat nicely inside then you would choose a smaller size template.
All templates are 1/4″ thick acrylic. They come with a protective paper or plastic coating that just peels off leaving no residue. The picture shows one of the hearts with its protective covering still on.