"If you think you are storing your digital records for posterity ... well, nobody is going to hang your hard drives on the wall. They want prints."

In my last column, among other things, we discussed archiving digital images and digital scans of film images. Almost without exception, most of the folks we know store their digital images on auxiliary hard drives. Because these are mechanical and can eventually fail, it's wise to back up to more than one hard drive. In fact, it's wise not only to back up to more than one drive, it's wise to keep one drive at a different location than your main backups. No good storing your life's work in one place if it burns down, is looted or, as happened in two cases I know of, a vengeful ex-spouse holds your work hostage.

Eventually, hard discs will probably be replaced by big versions of the memory cards that are in cameras. That will solve the problems of mechanical failure, but not the problem of marital failure.

Of course, none of this really matters because very few people outside of yourself care about your negatives or your discs of digital images. They want to see prints. If you think you are storing your digital records for posterity ... well, nobody is going to hang your hard drives on the wall. They want prints.

So, how long are digital prints going to be around?

We have a pretty good idea of how long film, silver prints and various conventional color prints are going to last. It depends on the material, the processing and the storage. We have a lot of experience with these materials, and their permanence has been studied by some wise folks. We don't have as much experience with the digital inkjet prints that will probably make up the majority of photographic prints over the next decades. The materials are evolving and changing even as they become the dominant medium.

Fortunately, we have Henry Wilhelm.

I first saw Henry Wilhelm's work in a book of photographs about the civil-rights movement in our country. He was a good photographer.

The next time I crossed his path was when he headed up a group in Grinnell, Iowa, making "archival" film and print washers along with drying racks. (The hypo-impregnated aprons on heated dryers could "unarchive" the best washed print.) They were made under the East Street Gallery name, a gallery he had opened in Grinnell in 1967.

I still have my film washer and the drying screens. The print washer was given away during one of many moves. The "instruction book" for these items was a 26-page pamphlet of good ideas and information (and a promise that Wilhelm would write a real book someday) entitled "Procedures for Processing and Storing Black-and-White Photographs for Maximum Possible Permanence." Pretty soon everybody was knocking off the East Street washers. But in the early 1990s, Henry's real book came out. And there was nothing else like it. Still isn't.

"The Permanence and Care of Color Photographs" was more than its title indicated. There were sections on black-and-white films and prints, motion pictures (Wilhelm served as a technical advisor to Martin Scorsese in his efforts to get Kodak and Fuji to increase the stability of their motion picture films.), mounting, matting, projecting, even spotting. Extensive, complete, detailed - it was the bible. And, for those caring for the treasure of film and silver or dye prints, it remains such. But the photographic world changed. It went digital.

And, while photographers were still arguing over whether it was worth it to "go digital," Wilhelm was testing the materials involved. "Permanence and Care" had already dealt with some of the early problems. (For example, anyone who had read the book was not going to use CDs as long-term storage medium.) But this new digital world was evolving and changing so rapidly that anything as fixed as a book would be constantly going out of date.

Thus, the Web site for Wilhelm Imaging Research.

Probably of greatest interest to photographers are the two sections entitled, "WIR Print Permanence Ratings for Desktop Printers, 4x6-inch Dedicated Photo Printers, and Silver-Halide Digital Minilabs" and "WIR Print Permanence Ratings for Medium-Format Tabletop Inkjet Printers and for Large-Format Inkjet Printers." I tend to read the articles for general information and to use the site's search engine to see if there is data on specific printers, inks and papers than I am using. (Often with new materials or equipment, there is an initial period of time where the reviews are adding new information as tests progress. So, with your new printer or new papers, it's worth your while to check into the site regularly.)

By checking into the site, you will be able to choose materials that suit your taste but also have good, lasting qualities. You will see figures on unframed prints, framed under both regular an UV screening materials, prints treated with sprays and prints in dark storage (boxes). You will see the difference between the life expectancy of color and black-and-white.

Figures can't be exact. Storage conditions are too varied as are individual standards for what is acceptable image deterioration. But Wilhelm's tests are tough and a far cry from some of the easygoing tests that let manufacturers claim results that are unrealistic in the real world. In general, I think most photographers will be surprised and pleased by the long lasting characteristics of some of the materials available to them, especially if they work in black-and-white.

Other sections on the site are background material on the folks that are Wilhelm Imaging Research, information on archiving valuable material at -20 degrees centigrade from their work with the Corbis-Bettmann Archive, technical articles that have been presented by members of the team and general interest articles on permanence and preservation from a variety of sources.

My favorite, however, is a daily news section entitled "Piranha Daily News: catching the news stream - technology, digital imaging, output, events." I have no idea why I am so amused by a daily news section on a site devoted to permanence unless it is a reminder that Wilhelm and his associates are not out of touch with the world of the working stiff, you and me. Henry Wilhelm was a pretty good news photographer. He may be the man to talk to if you run a museum or an historical collection of images. But he has done an awful lot for his brothers and sisters who are out collecting tomorrow's history.