The Giant Book of Duncan Yo-Yo Return Top Tricks
 
Digital Download
 
Donald F. Duncan Inc. (1961)
 
Book number 16
 
Pages: 32
 
People in the U.S. started playing with the British bandalore or yo-yo in the 1860s. It was not until the 1920s that Americans first heard the word yo-yo. Pedro Flores, a Philippine immigrant, began manufacturing a toy labeled with that name. Flores became the first person to mass-produce toy yo-yos, at his small toy factory located in California. Donald Duncan saw the Flores toy, liked it, and bought the rights from Flores in 1929, and then trademarked the name "Yo-Yo."
 
Duncan's first contribution to yo-yo technology was the slip string, consisting of a sliding loop around the axle instead of a knot. With this revolutionary improvement, the yo-yo could do a trick called "sleep" for the first time. The original shape, first introduced to the U.S., was the imperial or standard shape. Duncan introduced the butterfly shape, a design that reverses the halves of a traditional imperial yo-yo. The butterfly allowed the player to catch the yo-yo on the string easily, good for certain tricks.
 
Yo-yo sales reached its highest peak in 1962 when Duncan Yo-Yo sold 45 million units. Unfortunately, this 1962 hike in sales led to the end of Donald Duncan's Company. Advertising and production cost far outstripped even the sudden increase in sales revenues.