Sail Numbers. These large self-adhesive insignia fabric characters are what you see on sailboat sails. If you need large identification numbers or letters on barns, trucks, these are for you. To give you an idea of the size, the stop sign outside our building has 10 inch characters. We offer both 10 and 12 inch characters. The color we stock is black, but is available for quantity purchases in other colors. Contact us for additional details. We offer the full alphanumeric set.