The NYKE Fugu showed up at the shop, courtesy of Jim Peck, needing some tender loving care. The reason for the visit was a rip in the Fugu that was about 15 feet long. A rip is a rip, a tear is a tear, fixing such is usually pretty straight forward. Then things got interesting.
Rip repair for long rips: Rips are often fairly straight. That means that cutting a 1" wide strip of fabric to use as a patch is usually sufficient. It is rare, not unheard of, but rare, that larger pieces of fabric are needed.
The steps are: Identify, Stabilize, Seamstick, apply strip, sew.
Identify: Find the rip.
Stabilize: On the GOOD side of the material, on the outside or flyer side of the kite, apply 2" packing, masking, or duct tape (whatever sticks) over the rip to close it as if the tape is going to be the repair. Now the rip is ready to repair.
Seamstick: On the inside of the kite, or the side away from the flyer, check how well the sides of the rip align. Lift and arrange each side as needed until there are no wrinkles and the grain is aligned. Apply Seamstick (double side sticky tape with a mylar carrier. Quarter inch works well) to both sides of the rip.