This insert requires minimum resources while being very sturdy. It's designed to hold both Catan base + seafarers tiles (total of 51 hex tiles). It won't be as good for catan base tiles, unless you're willing to add a remixed print profile that makes it shorter to fit the base game tiles.
The top guard piece prevents the hexes from falling off if you store the Catan box vertically. It snaps down, and can be easily removed by pulling it up on a titled angle.