Removing Marker From A Box?
Try a damp magic eraser. If it doesnt remove it, it will at least lighten it a lot.
Storing Finished Craft Projects?
I like to use those plastic zipper bags that curtains, etc come in. I collect them from friends and family and store them until needed. They keep my projects clean and still allow some air to circulate. I do a lot of plastic canvas and these bags are great...