I'm having a flash sale of Batbases in various sizes that will last until 6th January. Batbases are MDF bases intended to accommodate entire units of up to two dozen miniatures for use with grid-based rules such as To the Strongest!
The irregular edges have a naturalistic look which blends much better with a base cloth than do rectangular bases. The bases are cut from 2mm MDF. Should you wish to magnetize the bases for transport, 3mm diameter magnets (sold separately) can be glued into the holes. The edges of the bases can be chamfered with a craft knife and/or sanded so that they slope down to the table surface. The bases are designed to fit in a four-liter Really Useful Box. The image above shows Wars of the Roses minis (not included) mounted on one of the 13cm-wide bases.
The on-sale Batbases can be found here, along with other sale items including Deep-Cut mats.