Most patches come with a foil layer on the tube side and a thin,\nfiddly, plastic layer on the side that will end up facing out. The\nfoil is easy to remove, but the plastic isn't. A page by Jobst Brandt\non Sheldon Brown's website says:\n\nThe backing paper or cellophane often has perforations so that it\nwill split in half when tube and patch are manually stretched. This\nmakes peeling the cover of the patch from inside to outside\npossible and prevents peeling a newly applied patch from the tube.\n\n[URL]http://www.sheldonbrown.com/brandt/patching.html[/URL]\n\nbut I generally find it fiddly. What's the reason for putting that\nplastic layer on patches?