I was in the market for getting some card sleeves for Star Realms. I came across these and decided to buy a pack to test them out. The quality is sturdy and thick. They fit perfectly snug around the cards just like I want them to. Even the black matte finish has a nice strong opaqueness to them. A brand I had purchased in the past was transparent and didn't too much care for the results. The packaging states the dimensions are 66x91mm while the Star Realms card size is the standard 63.5x88mm. Now, I already mentioned that they fit nice and snug on the cards, so I probably wouldn't recommend them for cards from games that might run a little wide or tall. At the rate of how often the Star Realms cards get shuffled considering it's a deck-building game, these sleeves definitely get the job done in protecting their longevity without adding too much added thickness to the cards. I also have a 6-deck automatic card shuffler, and these have no problem running through the machine. my brother and I are already planning on purchasing a boat-load more of these.