1940 Pepsi/Petty cardboard sign

[Greg Garrett]

I recently purchased a Pepsi cardboard sign. The artist is George Petty and is shown on page 63 of Warman's guide. The guide says the image is 11 x 21, but mine is 8.5 x 16. It seems original, the Pepsi Cola script and the bottle are embossed on the paper. Does anyone know any history of the two different sizes or their significance?