On Wednesday, March 14, 2018, 2:17:13 AM PDT, paul womack 
wrote:
 
 Thomas Conroy via OldTools wrote:

> Back to the point, a conservator will use water (or, actually, damp on a paper
towel); then detergent foam; and slowly up through alcohol to rougher solvents
if you actually must.

And BugBear replied: "Interesting - a lot of museum conservation is done with
manual mechanical methods (picks, scalpels etc), because they can be stopped
instantly. Any solvent (even water) can be hard to STOP.

"I guess books (perhaps fabrics too) require different methods."

  An excellent point, and one that I overlooked in trying to get to principals.
A dry wipe or hard brushing would be earlier steps. And notice tht the water
steps are done damp, not wet, and the detergent used is just the foam, not a wet
soapy rag. The idea is, as you say, to be able to stop immediately.
The actual procedure with books is quite a bit different, mostly because any
solvent except water is too rough for most books, but also because so few books
will bear the cost of wet treatment. Art-on-paper conservators do a lot more wet
and with solvents, but they have to deal with one piece of paper that may be
worth thousands of dollars rather than hundreds of piece of paper worth a
cumulative couple of hundred if everything is perfect. The cost is borne better
by art on paper. You can take your time, and still get paid for it.

Tom Conroy