Digital Image Conservation
The best way to preserve your digital images is to print them with archival inks on archival paper and put them in a dark place.
CDs, floppies, hard disks, go bad. Even if only a few bytes go gah-gah it could mean that the whole image is lost.
One (not infallible) way to protect against your CDs (and DVDs) going bad is to do roll-over preserving, which means every two years or so copy your photo files from an old CD to a new CD (or HD or USB disk). I'm not sure how many of us have the discipline to do that.
The good thing about paper records is that though they go bad, they go bad slowly. They fade, get torn, get scratched etc, but the image is still visible and reconstructable by the human eye.
Digitally stored images go bad suddenly. One day the image is perfectly readable, the next it is just gone. I personally have experience of CDs made on my computer in 2002 which today, in 2005, are just scrap. I may have been unlucky with a bad batch, but it can happen. And the older your backups the more likely it is that it will happen.
Even file formats can go bad. Say you have a disk full of JPGs. In 150 years your great grand children want to see what you looked like way back in 2005. Maybe JPGs are no longer supported by the new programs and computers. But a physical piece of paper, even 150 years old, will show the original image, if treated properly.
You should also consider preserving your old non digital materials by reprinting them with a good printer using good inks. I use RansenScan to scan old photos and an Epson printer to create copies.
An aside: Vellum
Believe it or not the British Parliament still uses vellum (parchment made from goat skin) for some of its records, because it has proven to be a reliable storage medium for at least 500 years. How many of you would bet on your photo CDs lasting that long?
A Mr. Vischer, who owns a vellum making company, said:
"Vellum has been proven to last indefinitely - that's the nub of the matter. If somebody wished to set fire to it maliciously with a match or an incendiary device, it would just go out. It's many times stronger than paper. If there was some physical damage to a building, the vellum inside it would be pretty much intact."
He was protesting at a plan to stop using vellum for the official records, read more here:
What we really need...
... I suppose is an archival printer which works with vellum....
but in the meantime I am doing my own experiments.
I have printed various A4 pages using an old EPSON 1290 (non pigment inks) and a newish EPSON Photo 2100. This latter is called an archival printer, and using the archival pigment inks we are told that there will be no fading, even after 75 years. Or was that "up to 75 years"? Anyway in 10 years I'll have a look at these currently identical prints to see if there are any real differences.
You could do something similar, there is nothing like personal experience to reinforce knowledge. Print three identical images, keep one in the dark, keep one behind a glass frame (protection againt UV light) and keep one unprotected on a wall.
Sepia photographs seem to have lasted well. You can get that old aged look of a sepia vignette using Repligator's Sepia effect with or without the oval frame. But remember to print and store the resulting image well if you want it to last!
One expert, Jon Cone, says that there is too much emphasis on archival materials and technology, when all that is really needed is education. If we know how to treat our artworks and photos properly there would be less need for expensive printers and inks.
These tips are not just for printed digital images, but all images on paper:
After writing this article I came across a paragraph in a magazine I read (Granta):
"The paper used in this publication meets the minimum requirements of American National Standard for Information Sciences - Permanence of Paper for Library Materials, ANSI Z39,48-1984."
If you subscribe to any magazines you want to last more than a couple of years, have a look to see if you can find a similar specification on the "info" page of the magazine.