These plastic registration pins, when paired with registration tabs, allow you to perfectly register colors when screen printing on paper and other flat stock. They especially come in handy when printing on papers with a torn edge, as the bumpers or traditional registration guides only work with perfectly square edges. Paper can also be hole punched to work with these pins eliminating the need for registration tabs, but be aware, some cheaper hole punches are actually 9/32" rather than 1/4", so they will not work with these pins. If you are unsure of your hole puncher's dimensions, it is recommended you just use the registration tabs with these registration pins.