The New York Times has a fascinating article comparing the methods used to preserve 35-millimeter movies and digital master records of movies. Conventional film can be stored in a limestone mine for almost nothing and last for decades. Pure digital storage is far more expensive and is likely to be more ephemeral.

You’ve likely thought of this when you’re storing your digital photos or home videos. Hardware and storage media have a much shorter shelf life than film or paper. Hard drives can freeze up within a couple of years if they’re not operated occasionally. CDs and DVDs degrade; their life span is variable but 15 years is a good rule of thumb.

As computer technology advances, file formats change and an archived file may become unreadable. A JPG or Quicktime file may seem permanent today, but are you confident that those formats will still be accessible in 20 years?

For the film industry, that means that digital archiving becomes a dynamic process where stored films must be re-archived periodically – far more labor intensive and expensive than storing traditional film.

It’s tempting to believe that our data has achieved more permanence on the computer than when it was on paper, but perhaps the opposite is true.