Have you noticed this difference in Switch game cards?

If you own a decent amount of Switch game cards, you might have noticed a difference in some of them. Some game cards have a green backing on them, while others are black. What's the deal with the change? While we don't have official word from Nintendo, a few people are saying that some game cards have a chip on a printed circuit board, while others are just the chip. No word on why Nintendo did this, but you can tell a difference between the two without even looking. One type of game card will rattle when you shake it, while the other won't!

from GoNintendo