Jim Henson's Designs and Doodles by Alison Inches to be a helpful title. With access to the Jim Henson archives, the author discovered many sketches showing the energetic muppet master's creative process. She arranged them into chapters recounting Henson's early career, his construction of muppets, his production of commercials in the late 1950s and early 1960s, and his efforts to get his own television show.
I enjoyed seeing early sketches showing the birth of characters who were only fully realized years later. Oscar the Grouch started as orange instead of green. Bert and Ernie came after a series of short-and-tall friends. Even Kermit was not a frog in the beginning.
Boomers can appreciate the book for different reasons than the teens. The author includes biographical and historical details that will remind them of their own early years. The publisher should should bring this fun book back to print.
Inches, Alison. Jim Henson's Designs and Doodles: A Muppet Sketchbook. Harry N. Abrams, 2001. 127p. ISBN 0810932407.