Lesson 3: Anatomy of a Stamp
We’ve previously discussed that stamps generally include the name of the authority issuing the stamp (usually, but not always, a government) and a value or denomination, in addition to other design elements. Stamp collectors also consider several other physical attributes of a stamp for identification and collecting purposes. Minor differences matter to advanced collectors: tiny differences in paper, color, design, or other attributes frequently reflect different practices in printing or distribution of the stamps and therefore help to tell more of the history of a particular stamp issue. Of course, any collector is free to ignore the minor varieties and focus on bigger differences if they choose! Physical attributes of a stamp can also be very important in the evaluation of condition (see lesson 7).
Here are a few more things that collectors look at:
Paper: Some stamps were printed on more than one type of paper, including colored or chalky papers, or sometimes paper with different textures, such as wove paper and laid paper. The paper type can be used to distinguish different printings or issues of stamps that were used over periods of time.
Watermarks: Many older stamps have watermarked paper as a security feature. The mark shows in the paper when held to light as a bright design or spot due to thinner paper in certain areas.
Printing Method: Some stamps were produced by different methods of printing over time – such as engraving or lithography. Different printing methods result in visible differences in stamp design and appearance, and sometimes in size. For example, when the United States changed from flat-plate to rotary presses, the need to produce curved printing plates for the new presses resulted in stamps that were a slightly different size than the earlier flat-plate varieties.
Perforations: Perforations (or now die cuts) are the holes in between stamps so that they can be separated for use. Philatelists count the number of perforation holes in 2 centimeters (usually between 10 and 14) as an identification tool.
Gum: While rarely useful for identification, the gum on the back of a stamp is a very important attribute for condition and value. Most collectors prefer their mint stamps to have complete, undisturbed gum, just as it came from the post office. Missing, disturbed or damaged gum reduces value. Of course, not all stamps were issued with gum in the first place!
You might also enjoy this glossary of stamp terms available from the website of weekly stamp newspaper Linn’s Stamp News.