http://www.lepoix.de/html/reference/stream...esign_index.htm

Though not directly talking about pen history, the points of this article, it seems to highlight some of the differences in pen design we see in the 1920s versus the 1930s among top makers. Take, for example a flat top Duofold and compare it to a Balance or an Eversharp Skyline. Maybe even compare a streamline Duofold to a flat top Duofold. I do think that pen makers tried to stay at the forefront of industrial design trends during this period.

I love the designs from this period:

Little attempt was made to distinguish between functional and non-functional streamlining. Whether moving or stationary, products were cased in sleek, aerodynamic bodies, emblematic of the 1930s obsession with speed and efficiency. At most speeds streamlined styling did not, in fact, save much energy and, in stationary objects, it saved none at all. These were secondary considerations as the style came to represent an embracement of the machine and the hope that it held for the future.

Streamlining was influenced by America's fascination with high speed and dynamism of form. The style first materialized in moving mechanical objects that featured aerodynamic shapes. Designers based their creations on the porpoise's ovoid body and the teardrop's unbroken surface. Throughout the decade, streamlined trains, ships, plans, and motorcars familiarized the collective awareness with this new form of design. Exciting footage of technological wonders in Paramount and Movie-tone newsreels helped to disseminate and popularize the progress and pathways of America's future

Interestingly enough, pens were among the first objects to gain "non-functional" streamlining. The Sheaffer Balance was an early mass-market item to purport to bring the benefits of "ergonomic streamlining" to the marketplace. That was in 1929, even several years before contemporary American cars (often the classic bellwether of design) gained a more streamlined look (remember that in 1929, the rather un-streamlined Ford Model A [and earlier Model T] and other such vehicles ruled the roads in the US, even before the crash in the fall of that year). I often wondered about this- normally your typical "big ticket" items revolutionize first. Automobiles and aircraft come to mind for sure. But ironically the simple fountain pen was among the first things to modernize to streamlining at the very end of the 1920s and in the early 1930s.

Maybe it was the quickest way to get a streamlined item into the buyers hands. A lot of people had seen it or heard of it but couldn't have it. You figure cars, bikes or whatever was not a small dollar item but a pen was easier to get to the masses and I'm sure made for good marketing.