| | Re: What type of paper do I use to print images for ...
You will need a photo editing program of some sort to make the round images. I use photoshop elements personally, but I have heard of people using gimp too.
I even think the new word (latest version) will do shapes for you and you might be able to use it, but I haven't tried it.
Use a xyro sticker maker to stick the circles to the bottlecaps. Have them printed at walmart, walgreens or target and they shouldn't bleed. Most of those machines use laser printing so there is no ink to bleed. I found Walmarts machines don't give as clear an image as Target, but that may just be at my stores locally.