Litko knows that paper models need a firm foundation to, and so have created new bases specifically made for them.
From the release:
We now have curved-slot bases for paper miniatures available in a variety of sizes and colors.
These bases are designed for use with tabbed paper miniatures, typically miniatures that are trimmed out with no backing. Simply adjust the height of the miniatures tab to 3mm or less and slip into the curved slot. The curved slot binds the paper figure into the base, while still allowing you to remove the figure after the game.