As with most collectibles, the time of manufacture of each Zippo lighter often affects its value and this valuable information can be found on the bottom of each Zippo storm lighter. From the mid-50s, date codes were stamped on the bottom. The original purpose was for quality control. The date codes have since become an invaluable tool for Zippo collectors. Most lighters manufactured between 1933 and 1957 can be identified by the style and model and the patent or patent pending mark on the bottom.

 

 

 

The appearance of the word "Zippo" found in the bottom stamp provides another clue to the dating. There have been three major changes, as shown on the left. From 1933 to the mid-50s, the word "Zippo" was stamped in block letters. The Zippo script logo was developed in the late 40s and introduced in the bottom stamp around 1955. In the late 70s, the logo was redesigned and it was incorporated into the bottom stamp in 1980.

 

 

 

 

 ZIPPO SLIM(R) LIGHTER IDENTIFICATION CODES / MARKINGS

 ZIPPO CLASSIC LIGHTER IDENTIFICATION CODES / MARKINGS