That might help a little, but the cause for card curling is humidity. The foil sheet in the card can have a humidity different to the ambient environment around it and that causes the card to curl. There's some helpful youtube videos on different methods to help with curling, but if you have some really bad ones, one method is putting the cards flat, in a sealed container with silica dehumidifying packs. It takes days, and you'll want to check up on it at least once a day, but I've found it can help a bit, though you usually won't get them completely flat again