Grosset & Dunlap red-spined library bindings
This format was printed during the mid-1970's, and was marketed to libraries. Because of this, it is quite difficult to find books in this format *not* used by a library.
Also of importance is that these printings were *official* printings by Grosset & Dunlap, unlike earlier library re-binds, which were done by unrelated binderies.
By the mid-70's, quite a few of the titles in the Bobbsey Twins series had been taken out of publication. Of the remaining titles in print at that point, the only title not published with the red spine was the final volume, which inexplicably retained it's purple spine (The final Nancy Drew library binding from Grosset & Dunlap also retained the yellow-color of the regular series, despite the remainder of the Nancy Drew library bindings being printed with lavender purple spines). Scans of this title are shown at the very end, front and back, and these scans came from an eBay auction (Thanks to Bill Land for alerting me to the listing!).
Also of importance is that these printings were *official* printings by Grosset & Dunlap, unlike earlier library re-binds, which were done by unrelated binderies.
By the mid-70's, quite a few of the titles in the Bobbsey Twins series had been taken out of publication. Of the remaining titles in print at that point, the only title not published with the red spine was the final volume, which inexplicably retained it's purple spine (The final Nancy Drew library binding from Grosset & Dunlap also retained the yellow-color of the regular series, despite the remainder of the Nancy Drew library bindings being printed with lavender purple spines). Scans of this title are shown at the very end, front and back, and these scans came from an eBay auction (Thanks to Bill Land for alerting me to the listing!).