How to choose the right size? make sure your cards size is smaller than the sleeves, for example, your photo cards is 55x87mm, choose the sleeves size at least 56x88mm. BlackLotos card sleeves are Acid Free and NO PVC,they won't do harm to your cards. BlackLotos Sleeves one side is clear and the other is shinny foiling, you can put the cards on the shinny side or the clear side depends on your choice. BlackLotos sleeves are all top inserting, you put and take cards from the top part, its easy to put the cards in your binder or albums, the card won't slip off. we have many different styles, and they are designed for ygo cards, you need to choose the style you like before ordering. Black Lotos packing is 100ct each bag, it will come many, if you have a lot of cards, you can just buy more packs.