Ask Slashdot: Best Way To Store Data In Hard Copy? 329
First time accepted submitter bmearns writes "I have some simple plain-text files (e.g., account information) that I want to print on paper and store in my firebox as a backup to my backup. What's the best way to encode the data for print so that it can later be restored to digital form? I've considered just printing it as text and using OCR to recover it. The upsides are that it's easy and I can even access the information without a computer if necessary. Downsides are data density, no encryption, no error correction, and how well does OCR work, anyway? Another option is printing 2D barcodes. Upsides are density, error correction, I could encrypt the data before printing. Downsides are that I'll need to split it up into multiple barcodes due to maximum capacity of popular barcode formats, and I can't access the data without a computer. Did I miss any options? What do slashdotters suggest?"
One word (Score:4, Interesting)
QR codes. You can encrypt these. If you print them e.g. on plastic foil, they'll last close to forever. Of course, you will need to keep a piece of hardware that can read QR codes.
I would, however, take another route, although outside of the scope of your question. It is something I already do for files that are very valuable to me: I put them on magneto-optical disks. The things last forever and withstand the roughest of treatments. Writing and reading are slow, but that is a downside I just accept. I still have a database ( invaluable to me ) I acquired in the middle '90s on magneto-optical disk. It survived: a fire; spilling of liquids, including dog pee; some mild X-ray radiation; an inadvertent stay in our home's trash can; being jumped upon by a kid; and a 20-foot fall.
Re:Text, but why? (Score:5, Interesting)
And as long as a decent font for OCR is used - like OCR-B then it should be feasible.
The reason for doing it - well, if you want to preserve something for a few decades then it's printing on lint paper and using ink that can survive a long time. The latter is probably the hardest since nobody really knows which kind of ink used in computer printers that's able to survive for centuries.
My suspicion is that the dot matrix printers are better off than lasers and inkjets.
Have you seen this... (Score:4, Interesting)
...post on Dan's Data already?
He covered most options available for what you want back in 2009, and apparently he did an update in 2011.
http://www.dansdata.com/gz094.htm [dansdata.com]
Re:Text, but why? (Score:4, Interesting)
It can actually be a risk, if the fuser doesn't get the toner hot enough, long enough, to fully infiltrate the paper(without burning it, obviously, which is presumably what drives conservatism on that score).
Very high humidity at print time can be a problem: It's rarely this dramatic; but I've seen a few cases where paper, left unattended and non climate controlled through a ghastly humid summer, to the point where it starts to get vaguely limp, billowing steam as it passed through the fuser stage. An interesting spectacle; but, needless to say, not good for adhesion(the characters themselves, while delicate, were largely intact, and could be poured off the paper), since the enthalpy of vaporization of water was sinking significant heat at point of contact. Sometimes the classier laser printers have humidity sensors in the print path to compensate; but air conditioning still isn't a bad idea, if only for the poor humans.