It seems like a lot of people are having trouble making Bonk! cans. The main problem seems to be the part where the tops and bottoms of the graphic are scrunched creating a hideous abomination.
Therefore I have decided to post this tutorial on how to make cans that look right. It's really easy, I swear.
Step 1: Using painter's tape, isolate the top and bottom of the can. This is a very tedious process. Take your time and use several small pieces as opposed to some large piece of tape all around.
LIGHTLY sand the can of choice (probably 120 grit and higher). The reason you do this is to create small scratches in which the paint can 'fill in' and create better adhesion.
After the sanding process, rinse the cans with water and dry them completely.
Step 2. Paint the can with spray paint. I personally use Krylon. Make sure you spray in light layers over a period of time. Avoid spray painting all at once or else you will have uneven spots of paint.
Step 3. When you print out the Bonk! label, cut off the top and bottom solid areas. Use spray adhesive to adhere your label to the can. Do not overuse spray adhesive. A fine misting will do. I would not suggest Elmer's glue or rubber cement because it will cause your label to wrinkle.
Step 4. Step back and marvel at your handiwork. Saxton Hale would be proud of you.
(Technically, if you want to make the can the right way, you need to find a manufacturer that is willing to put the design on a can. Unfortunately, this endeavor has proven difficult for me so this tutorial provides the next best thing.)