If you are a ballpoint pen lover, switch to black ink when security is important. Among water-based inks, remember that gels are the most impervious. But when you're writing checks to pay the monthly bills, only one type of ink, the kind in gel pens, has been found to be counterfeit proof to acetone or any other chemical used in "check washing." Most ballpoint and marker inks are dye based, meaning that the pigments are dissolved in the ink.

"Assuming a non-Hollerith encoding with eight bits per column, and an MP3 file encoded at 128kbps CBR, there would be 36,864 cards in that deck, and the card reader would need a throughput of 205 cards per second. It might be wise to include an 8-column sequence number, however, so that a misordered deck can be repaired by a card sorter; with 72 data columns per card, the total is precisely 40,960 cards (40K cards), requiring a 228 card/second throughput." The 21 boxes of cards needed would by 5 feet 9 inches tall. That such a huge leap in technology is well within living memory astonishes Y.