John Thomas Coulthard was a commercial artist/cartoonist who was active from the 1920’s until the 1960’s. As a philtatelist and cachet maker, he is interesting to poster stamp and ephemera collectors.
Here is just a bit more to add to the above article. The bookplate label shown in brown earlier is also seen in blue, shown with and without somone’s personal information added in, all are approximately 3″ by 4.25″:


Also found, an advertising cartoon printed in light green, it does not seem to have been gummed, approx. 2.2″ square.

–T. Minor with a bit from Joe Ward, special thanks to Doug Henkle for his website. Revised August 12.