>I've been given a rather large collection of German stamps and catalogs for
>rating them. For a few of the stamps the catalog notes that their gum
>contained sulphuric acid, that most collectors remove the gum, and that the
>listed "unused" prices were for stamps without gum.
>I have two of the stamps in question, unused, with gum.
>Should the gum be removed? How?
The presence of the sulphuric acid can in the long run damage the
stamps. It is therefore adviced to remove the gum.
I suppose that putting the stamps in some half warm water will do.
Maybe it's wise to use two portions of water, one for washing and one
for rinsing. I'm only not sure how the ink reacts to water (probably
it doesn't) but I'm sure somebody out there on this newsgroup knows.