I can second the recommendation on sail tape. Or sail repair tape, as it may be called. BUT.. I bet you'd have a hard time if you tried to strip off a bit to create a smaller roll or packet for your PSK.
[ah.. the nightmares. Waking up on deck in the cove on Jost Van Dyke island with a bottle of Pusser's Rum sail-taped to my hand... took me all day to get it off and get that adhesive off of me. The culprit wouldn't help] That tape is waterproof, soap proof, booze proof, cuss proof, tear proof, sunscreen proof... but NOT lighter fluid proof.