The first book in this Stratemeyer Syndicate series, The Bobbsey Twins or Merry Days Indoors and Out, was originally published by Mershon in 1904. The second and third volumes were published by Chatterton-Peck in 1907. The Syndicate revived the series in 1913 and subsequent titles, and reprints of the first three volumes, were issued by Grosset & Dunlap. The early G&D editions featured white spine dust jackets with a circular spine emblem declaring "For Children of 5 to 10 Years." The books were bound in green cloth with applique covers that matched the artwork on the dust jacket. The pink spine dust jacket editions were in print from about 1940 through 1949. At least 38 titles were available in this format. The quality of the paper used in these editions is inferior to earlier print runs and later formats, due to the wartime paper shortages. The blue spine dust jacket editions were in print, for selected titles, from about 1950 through 1962. In 1955, G&D switched to the wrap-around illustrated format for all new editions and all revisions and reissues of earlier titles. In 1963, the format was changed to the lavender spine picture cover editions. Much to the dismay of collectors, only 56 of the 72 hardcover Bobbsey Twins titles (#1 through 20, 24, 25, 27, 35, 38, 42 through 72) were issued in this format. Some of the final picture cover printings dispensed with numbers entirely to hide the fact that 16 titles had been allowed to fall out of print.