Common in professional kitchens, painter's tape and a good marker should be a part of a home kitchen as well. It works best on deli cups but it can be used on most surfaces. Better, it can be removed from them as well, without leaving stickiness behind. (Photo by donna, thanks sweetheart!)
I store a lot of stock in a basement freezer and every container gets marked and dated. Don't even think you'll remember what that stuff is under all that frost. Don't think you're going to remember how many yolks were left over from making angel food cake.
I first saw blue painter's tape at The French Laundry years ago. Thomas Keller's restaurants now use green painter's tape because, I believe, it's even cleaner when removed than the blue stuff (more expensive too). I like blue just fine, and ...
