Jeremy Brice had a question in MMD 980921 about shellac solution for
book music.

I do not know the amount of shellac in French polish. The proportions
we mostly use for shellacking book music in the Netherlands are about
125 grams of shellac on 800 grams of methylated spirit (you could use
ethanol, but that is too nice to drink, and too expensive in most
countries :-). Be sure to use the strongest methylated spirit that you
can get (I use to buy it in France, because it is 90% strength there,
and without colour so you can use it to make polish with it).  Depending
on the quality of the cardboard this solution can be diluted slightly
when the cardboard is taking up only little of the solution, and more
(up to 200 grams) shellac should be added when the cardboard is of a
bad quality.  When the solution is working well it is a good idea to
add up to 5% of graphite powder to the solution. Stir well and often,
because the graphite will keep sinking in the solution. The result
should look light to medium gray, not black.  Cardboard books treated
in this way may not look so attractive, but they will last longer, and
they will keep your keys in a perfect condition.

Good luck!

Hans van Oost, KDV, Netherlands