As seen with these figures, I’m basing my skirmishers on individual 25mm square bases by Litko. Starting with .8mm plywood bases I then back them with the same size heavy duty magnetic pieces, also by Litko. I think the resulting thickness is sufficient without being obnoxious. Basing my skirmish infantry individually gives me the flexibility to play a number of skirmish games yet easily conform to the basing standards of British Grenadier. The magnetic bottoms are nice for storage and transport.