Not many American companies can trace back their roots more than 200 years. DuPont is one of those. Organized in 1802 in Delaware - where it is still headquartered - DuPont is a multinational chemical company. Its first product was gunpowder, and that was its primary product until its expanded in the early 20th century into dynamite and smokeless powder and later into a multitude of chemical products that we all use day in and day out.
One of DuPont's products in the early 20th century was Fabrikoid, a brand of artificial leather that was heavily used in the 1920s to upholster car seat covers and the tops of convertibles. The production of Fabrikoid was a nice complement, I'm sure, to DuPont's significant investment in General Motors that lasted from 1914 to 1957.
DuPont had a clever way of promoting Fabrikoid and that was to ask, "How Many Hides Has a Cow?" The slogan is stamped on the back of this ad cover (Figure 2), and I found what appears to be a full-page ad for Fabrikoid that ran in Collier's in 1915 (Figure 3).
Of interest from a postal history perspective is that this cover (Figure 1) is an example of 3rd class mail. Two items of note mark it as 3rd class mail: (1) the "dumb" postmark with no month or day only the year of 1918 and (2) 1-cent worth of postage, which was the 3rd class rate in 1918. The stamp that is affixed is US Scott #490, a very common stamp from that era.
The reason for the dumb postmark was so no one could track how long it took the Post Office to deliver a 3rd class letter (i). The cover probably contained a DuPont promotion or perhaps even a sample of Fabrikoid that could be requested for free from DuPont (see the bottom of the Collier's ad).
The recipient of this letter was another household name: John Deere, specifically an office in Syracuse, New York of what was then known as the John Deere Plow Company. John Deere can trace its origins back to 1837.
(i) U.S. Domestic Postal Rates, 1872-2011, Third Edition, Henry W. Beecher and Anthony S. Wawrukiewicz, p. 153.
Figure 1 - Front
Figure 2- Back
Figure 3 - Fabrikoid Ad from 1915