The repair you reach for when it is raining and sewing is not happening. Peel, press, carry on.

It is ripstop nylon with a proper pressure-sensitive adhesive, not duct tape. That matters because duct tape leaves residue, fails in the cold, and comes off the first time the fabric gets wet — all three of which you discover at the wrong time.

Round the corners of the patch before you stick it down. Square corners lift.