I got several end rolls of pretty heavy stock from a local book manufacturer. Most are around 30" wide by maybe 60 feet long. I take a 3/8" washer and color the hole with a black or red Sharpie. The dots are just a hair over 1/4" and are easy to see. I have the dots about 4" apart and usually have around 20 or more targets per sheet to use when load testing.