The idea is to create a permanent, not archival, copy that can go back on the shelf. A copy could also be kept for archival processing sometime in the future. The Cornell results show quality of the output document equivalent to or in some cases, better than the original. The solution is inexpensive, practical, and effective. The requirement for high-resolution greyscale imaging and the cost of optical disc storage is a major reason why archival preservation using imaging technology is still substantially more costly than archival filming.
Film is the least costly storage media.
A 125-foot roll of film, created to RLG preservation specifications, can contain about 2,700 nine inch pages at a reduction ratio of 12X with two pages per frame. In this particular example, optical disc storage costs are 20 times more expensive than film. However, advances in imaging technology, cost reductions in the digital storage costs, and increasing costs for preservation filming argue for using film as necessary to satisfy critical needs, but beginning the switch to the hybrid digital image preservation system as soon as technically feasible.