Golden Age Illustrator: Kay Nielsen
(Find me at 50 Watts Books.)
Kay Nielsen, illus. for Andersen's story "The Tinderbox" (see the original post) [Tinderbox!]
Though this is my first post on Danish-American illustrator Kay Nielsen (1886–1957), his influence can be seen everywhere on 50 Watts (try Lathrop and Sterrett).
The Golden Age have done a great job of archiving Nielsen's work online—they made most of these scans. (Update: RIP Golden Age - I removed the links.) Calla Editions have reprinted East of the Sun and West of the Moon: Old Tales from the North and will soon reprint In Powder and Crinoline (wisely re-titled The Twelve Dancing Princesses).
December 2015 update: Taschen has published a beautiful-looking slipcovered edition.