On Patreon, Cze and Peku released some awesome train carts, that will perfectly suit an Eberron campaign. I've printed these on banner cloth, and wanted it not to fold during the game.

So I've made an OpenLock compatible holders, to use with other terrain pieces I've got.

One cart is two parts bottom and two parts top, that is 5x14 inches assembled. Round magnets 8x1mm are required for this to work. 36 in total per cart. It's also possible to use 8x2mm for the bottom part, in this case it'd be 12 8x2mm and 12 8x1mm.

It's possible to make it work without an OpenLock, in this case I suggest to use four top parts. Refer to picture.

It's possible to use other sizes, but these are the magnets I've had at hand. These could be bought dirt cheap on Ebay.

Also I had great success in using OpenLock Magnetic Connection System, definitely would recommend that.

Be sure to let heatbed to cooldown before removing parts, since it tends to bend while hot per my experience.