One vinyl window on our Northstar TS1000 had ripped away from the stitching at the corner. It's a general problem on our camper since I think the vinyl was sewn just a little too short on the corners on most windows. So I ordered a yard of 12 gauge tinted vinyl from Ebay and went to work. In retrospect I think untinted vinyl may be better since two layers of tinted vinyl at the patch appear darker than the rest of the window. The pictures should speak for themselves. Took me about 45 minutes or so for the repair with the longest time spent on the hand stitching.