I think the main reason for covering tattoos is to catch the ink and other stuff that oozes out for the first day or so, as well as to stop other bacteria getting in while it's still open. Different artists have different advice and it might depend on what products they use as well as everybody's body differing, so the advice I've always seen is just to follow your artist's advice. For my first tattoo I had the adhesive cover for about 30 hours and took it off in the shower, my last one I just had cling film masking taped to me overnight and it healed really well. The main things are keeping it clean, moisturised and not to let clothes rub on it/not to lie on it for a while. I've heard recovering is bad though as once you've uncovered it once, you don't know what you're trapping in there.