| | Free Bottle Cap Templates
This site has free templates including 1" circle:
go to gogocakes dot com - there are several different template sizes
There are 2 sites on Youtube for using templates with GIMP.
I bought from every seller on the net, but I can certainly whole-heartedly recommend Etsy user purple8p. For just $4, hers was the best tutorial (I had no problems moving around my images under the template) plus you get a choice of 3 different sized templates. And she is an extremely patient person who answers all your questions very quickly.