This is a perfin for the State of Illinois (state government official use, presumably). The outer shape is supposed to be a map of the state, so you have your illustration upside down (the northern border between Illinois & Wisconsin is the straight horizontal bit which your illustration has at the bottom). The inside pins then create a capital letter "I". There are two different listings with tiny differences, small enough that I can't really use your illustration to tell which one is which. The more common one (rating F, the most common rating for US perfin stamps) was in use from 1922-1965 and can also be found on precancelled stamps. The somewhat less common type (rating D) was in use from 1917-1923 and is not known on precancels.
I thought it was a state, but I never thought it was upside down, so I never thought Illinois. I know it's pretty common because I have quite a few with this pattern, however, you're right. I actually can't tell any differences, unless I have all common ones, which is probably the case.
Can anyone give me a good resource for locating information about Perfins? I tried perfins.org but I don't like the way they display the images, it's still very hard to make out on their website. Thanks for your help.
bcuddy , I wonder if it might be ESSO, the trading name for Exxon fuels.
My catalogue for US perfins lists this ESSO perfin as belonging to the Standard Oil Company in New York, NY. Have a look at this Wikipedia page for Standard Oil, the name of John D. Rockefeller's oil company which existed until losing an antitrust case in 1911 which caused the breakup of the company. The portion which turned into Esso, later Exxon, was the Standard Oil Co. of New Jersey. A second portion, the Standard Oil Co. of New York, later became Mobil. (And eventually in 1999, Exxon & Mobil merged back together!) So, perhaps the catalogue is wrong and the company location associated with the Esso perfin should be somewhere in New Jersey. Then again, perhaps not - although the NY portion had the rights to the Esso name in New York state, apparently the NJ portion did operate some stations in New York under the Esso name. What a mess!
Apart from Esso & Mobil, other names familiar to North American drivers which came out of the Standard Oil breakup include Amoco, Chevron & Marathon, among others.
You can find a listing of USA perfins on the Philatelic Geography site run by Zenonas Zebrauskas of Lithuania. His site uses frames, so you'll have to go to the bottom of the page and click on "Home" to get back to the main page and then click on "Enter" to restore the frame structure. Unfortunately, most perfin listings are missing images, which isn't a problem for your "ESSO" perfin since that's unique to Standard Oil but does become a problem for some other abbreviations found on perfins.
Your perfin is given a rarity rating of "E" - the scale goes from "A" (most rare) to "F" (most common).