Every little piece of plastic saved adds up right? So instead of covering the little bit of leftover tuna with plastic wrap, use a wide-mouth canning jar lid!
I know we’re not supposed to keep the tuna in the can at all (or even buy tuna in cans in the first place), but I don’t need any extra dishes in my sink thank you very much. I open the can, drain the water out, mix the mayo in right there in the can, apply to sandwiches and, if there’s any leftover at all, snap a lid on and put it in the fridge. It gets eaten up so soon that I have decided not to worry about it.
The wide-mouth lids fit so perfectly they seem like they were made for tuna cans.
calamity jane 
Penny for your thoughts…?