I designed these bases for infantry battalia in For King and Parliament. They are cut from 2mm MDF; 3mm diameter magnets (sold separately) can be fitted into the holes to secure them in storage or transport. The edges of the bases can be chamfered with a craft knife and the naturalistic appearance of the wobbly edges helps them to merge into the playing surface. 

This pack includes three bases, making a unit 19cm wide for use with a 20cm grid. The FK&P6 bases are approximately 60mm wide and 70mm deep. They will take 18 minis if two ranks deep or 27 minis, if three. The attached image shows two ranks with additional command in front.