I also use steel bases, and not for their magnetic properties. They are thin, so it does not look as though your troops are on a yard-high plinth. And they add a nice "heft" to the piece, which is also more resistant to joggling out of position at the lightest vibration. They don't flake, chip or warp. In the UK we also have a supplier of pre-cut bases:
http://www.freewebs.com/pwsltd/steelbases.htm
He has a wide variety of shapes and sizes designed for various rulesets (a lot of 40mm wide items) and he will cut to order too. For WW2 and Modern I put my troops on 1" square bases (or 25mm square if you prefer). One vehicle or gun, or about half a dozen infantry. Depending on the level of the rules I am using they may represent anything from a section or squad up to a platoon or a company (in Panzer Korps, for example). I like to do a bit of landscaping on the bases, especially for command elements and anti-tank guns.
Questions about WWII infantry basing for gamers
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