Perhaps my favourite bit, though, is that they tried to initiate the reaction using starting points other than fingerprints; they found that tiny residues of inkjet ink would show up brown as they started the polymerisation. Again, the limit is so low that they could even highlight the ink residues on the envelope a document had previously been in. With a bit of Photoshopping you could actually tell what text had been printed on the document, without ever seeing the original. Nifty eh? Here’s a sample:

With a bit of Photoshop and a bit of imagination...

For more detailed info read the Chemical Technology story posted recently.