Proofreading on paper

There are a few practical aspects to be sorted before we can say that this is the "beginning of the end for paper-based proofreading".
For example, I feel that proofreading against copy is easier with the (paper) proof and the original text side by side. And, although dispatching proofs to the authors and specialist editors of multi-author books, as well as the proofreader and indexer, will be easy--as it is already when these people are sent PDFs--I suspect that collating all those sets of paperless proofs will require careful thought and organisation.
Even collating just three sets of paperless proofs--one proofreader and two authors, or two proofreaders and one author--might not be as simple as it is with all the paper proofs laid out in front of you.
However, the pluses of speed of dispatch and return, ease of marking amendments, and the removal of the problem of proofreaders’ unclear writing (and perhaps out-of-date symbols!) are definite boons.
This system will prove extremely helpful and I look forward to trying it out myself.