Have about 10 framed and none are in bags. Some 
people think it helps keeping them in the bags to 
prevent fading but I don't agree, if they are 
gonna fade, bags won't make a difference. 
 (yes, mine are DbZ Toei cels that just love to  
fade, so far they are in good shape (over a year 
now). Oh well, if they fade so be it. I am not 
gonna stress over it. Too many other things to 
stress about these days)