I made this for hobbies and also helps to organize the card piles on the battlefield. You can use it as your library, graveyard, exile or even your commander zone.
The card tray holder is design for card size of magic the gathering, you will find it is fit to the card sleeves. You can stack them, connect to each others at top, bottom, left and right side.
Print it and use it, as simple as that :)
I will post for Island, Mountain and Forest in future.
Enjoy the card tray and Enjoy Magic the Gathering.
Ps: would appreciate if you tip me :)