to mark line where canopy contacts forward bow of canopy frame i just used a method that works like a million bucks
first lay a piece of regular masking tape along the bow. next cover the bow with a loose wrap of carbon paper. now when the canopy is set in place you get a sharp line on the masking tape where the canopy made contact.
first lay a piece of regular masking tape along the bow. next cover the bow with a loose wrap of carbon paper. now when the canopy is set in place you get a sharp line on the masking tape where the canopy made contact.