The boys’ daycare asks that all food containers be labeled with the child’s name, and most parents write the name right on the container with a Sharpie. From the earliest days, when my oldest was just a baby starting on solids, I’ve been extremely hesitant to write directly on the container – I have visions of the black ink rubbing off in the dishwasher and specks of it getting on everything.
Instead, I affix a small piece of masking tape to each container and write the appropriate child’s name on it. When I’m doing dishes at night, I simply pull the tape off and put the container in the dishwasher. Masking tape comes right off and there’s no residue, plus one roll lasts for over a year – my oldest has been in daycare for about three years, and I’m just finishing up my second roll of tape.
The masking tape works great on any plastic container that goes in the fridge, too. But it tends to peel off in the freezer so I don’t recommend it for that.