jon said:

If the purpose of scans is for multiple use cases (and not only OCR), then it appears wise to scan text at 600 dpi, preferably 24-bit full

color

except over at d.p., their reason for scanning is to do o.c.r., for proofing. but perhaps other projects, like million-books or internet-archive, would find your position persuasive. or maybe not.

Of course, the huge downside to higher-rez, higher-color-depth images are much greater file sizes. This causes difficulty with online archival storage and transport.

that's only one huge downside. another huge downside is that scanning takes _much_ longer. indeed, i would say that _that_ would be their primary objection. most d.p. scanning people are processing lots and lots of books, and do not have the time to spare to create scans at a resolution that is far higher than what they require to do the job that they set out to do. as always, it has everything to do with the cost-benefit ratio. you can rave all you want about the benefit, but if people don't want to pay the cost... -bowerbird