This insert is designed to fit inside the core Mage Wars box (not Arena).  The image above shows my single core with all expansions released to date.  As you can see, there is plenty of room for you to store your cards however you want and still have room for future expansions.

Product Notes

• This insert measures 69mm high and provides four (4) organizational lanes for horizontal card storage. There is ~12.5mm of top clearance allowing for the storage of the game board, rule books, and player boards.
• External dimensions: 412mm x 309mm x 69mm high (16.22″ x 12.16″ x 2.71″)
• This insert has lanes that are 99.25mm wide allowing for the use of most card sleeves. Recommended sleeves include Ultra Pro Deck Protector and Mayday Premium.
• This insert has 1188mm of card lane storage.  It can store ~3960 unsleeved cards or ~2376 Mayday Premium sleeved cards (.50mm per card) or ~2200 Ultra Pro Deck Protector sleeved cards (.54mm per card).  Keep in mind each acrylic divider will also use 2.286mm of card lane space.  The values used for the card thickness estimate = .3mm.
• Insert assembly requires some wood glue and about 15 minutes of assembly time. I recommend Sobo Craft glue or another comparable quick setting, tacky glue.
• Image is of prototype using 3mm Baltic Birch. Production insert uses HDF wood product.
• This insert is constructed of HDF (wood product) and is natural colored. HDF does not contain a wood grain as it is a constructed wood product.
• Includes fifteen (15) clear acrylic dividers (model MW-DIV-002). Additional divider packs of type MW-DIV-002 should be used. The DIV–002 design allows for the attachment of Post-it Durable Hanging File Folder Tabs (adhesive) for divider notes.This is a third-party, non-licensed product.
• This is not a licensed product.