Man, this hits home because I used to swear by the plastic wrap method for years. Thought it was the best way to keep everything from drying out, and I told people about it like I was some kind of expert. Then a friend who actually went to school for this showed me the cap and paper thing and it honestly blew my mind. The wrap traps heat and can make the color process way hotter than it should, which messes with the result. Paper lets things breathe and gives a much more even lift. Now I feel kind of dumb for all those years of fighting with cling film that kept slipping off.