It depends where it is. I have 3 tattoos. One on each wrist and one on the side of my neck. When sleeping I didn't cover them. Usually you do not want to have them covered long. This keeps them from healing and will actually cause scabbing which will not only itch but it will cause your tattoo to peel off. Where ever it is on your body, when you sleep, don't wear clothing over it. Put some ad ointment on it before laying down and when you wake up, rinse it off with soft soap antibacterial soap and apply new ointment.