Whatman's various "FTA" products offer a convenient way to store/archive various DNA-containing samples at room temperature in the filter paper format that takes very little space.

The whole line of FTA offerings has been built around a very simple idea that people used for many years when sending plasmids by mail: spot DNA on a filter paper and let dry. And in the case of FTA cards, one can spot not just DNA but also cells. Hence the "CloneSaver" products.

This "technology" is described in the multitude of US patents by inventor Leigh A. Burgoyne with Assignees either Flinders Technologies or Whatman. E.g., patent # 5496562. 

So FTA cards are just a thick filter paper with dried Tris, EDTA and SDS. You spot cells onto it, SDS lyses them, EDTA inhibits nuclease and once the whole thing is dried, DNA is stable enough. (Heck, if we can sequence some of the Neanderthal DNA > 30,000 years old!). Quick wash with TE removes some DNA and most of the SDS/EDTA, then more DNA is eluted and used for transformation (when storing clones) or PCR. For cleaner things, phenol and/or isopropanol washes can be added before elution.

The original patent describes this: 50 ul of 2% SDS, 10 mM EDTA, 60 mM Tris solution spotted on 1 cm2 of Whatman 3MM and dried. FTA kits have some other filter paper, thicker than 3MM but it really should not matter that much. At least for E.coli, the concentrations may be an overkill. Long ago, before Google patents existed and I wasn't sure what FTA cards are, I soaked some 3MM in just TE + 1% SDS, removed the paper into sterile petri dish, let it dry there and spotted 5 ul of several overnight cultures. A year after, storing cut pieces in the drawer, all clones gave lots of transformants after electroporation with eluted samples.