I've been printing targets for years. Started when I needed a 10 meter target that duplicated the difficulty of the 600 yard high power rifle target, to let me practice in the basement with an air rifle. Back then I calculated the ring sizes relative to each other, drew a single target with a compass, photographed it, carefully enlarged it to the correct physical diameter and printed multiples on a single sheet of glossy photo paper. Then with that "master target" I went to my office copier and printed what I needed on manila brief covers (110 pound, ivory) which stands up much better than ordinary typing/copy paper.
It's a lot easier today with these sorts of templates, but I still use the heavy ivory paper. Here's another source with links to specific types of targets: http://www.recguns.com/targets.html
Here's a pic of the stencil and targets I've made from the cardboard dividers that come in 30-packs of beer. Simply cut out the center circle of one, lay over top of the others and spray paint with the color of your choice.