Take a look at what can be found on the backs of stamps

By Janet Klug

We collect stamps because they are beautiful and interesting, but being attracted to their designs and stories often means that we seldom give the backs of stamps more than a cursory glance.

The backs of stamps can be quite interesting. Most collectors will flip a stamp over prior to purchase to ascertain where there is a paper thin or, in the case of an unused stamp, if it has full original gum or a hinge mark. The condition of gum can make a world of difference in the price of a stamp.

Similarly, a stamp that appears nice from the front may well have a hideous thin that can be seen from the back. Such stamps may fill the spaces in an album, but a damaged stamp seldom has much in the way of residual value when the time comes to sell.

If it is printed on watermarked paper, looking at the back of a stamp can also reveal the watermark.

Although few new stamps have watermarks, watermarked paper was used frequently in days gone by as a security measure implemented to make stamps more difficult to forge.

Stamp collectors pay attention to watermarks because the presence or absence of a watermark can result in a substantial difference in value for two stamps that might otherwise look the same.

Grills can be seen from the backs of some stamps. A grill is a textured pattern pressed into the paper on which a stamp is printed.

The process of impressing the grill would break the fibers within the paper so the stamp would better absorb cancellation ink. This was supposed to hinder the removal of the cancellation and prevent the reuse of the stamp, but it also made the stamp weaker and more difficult to tear without damage when removing it from the pane.

Grills were used on United States stamps from the late 1860s to the early 1870s before being abandoned. Figure 1 pictures a grill as seen on the back of an 1869 3¢ Locomotive stamp (Scott 114).

All manner of things have been printed on the backs of stamps, and there have been many reasons for intentional back printing.

In 1893, New Zealand sold advertising space on the backs of stamps bearing the portrait of Queen Victoria. All sorts of products were marketed on these stamp backs, including cocoa, soap, pickles, coffee, coal, sewing machines, cough syrup, and even the opportunity of having your ad placed on the back of a stamp.

Shown in Figure 2 is the back of a New Zealand 1-penny stamp (Scott 61) with an advertisement for "Truebridge, Miller & Reich, Wellington, Contractors for Advertising on Stamps & Telegraphs."

In 1886, Sweden issued stamps showing King Oscar II. A post horn, the symbol of the Swedish postal administration, was printed on the back of these stamps. The back of a 10-ore pink stamp (Scott 45) is shown in Figure 3.

The most common use of back printing is for control markings. Control markings can be numbers that help post office clerks keep track of the stamps they are selling, or they can be other markings that make sorting stamps faster and easier.

Shown in Figure 4 is the back of a Brazilian 100-reis Petroleum stamp (Scott 515) issued in 1941 with a control marking of three green lines.

Figure 5 depicts a control number on the reverse of a 1974 Swedish 75-ore King Carl XVI Gustaf coil stamp (Scott 1068). This type of number helped postal workers determine the number of stamps remaining in the large rolls from which some stamps had already been sold.

Tonga's round embossed foil stamps from the 1960s had traditional moisture-activated gum.

Today, stamps such as these would probably be self-adhesive, but 40 years ago the stamps were produced with a foil layer on top of a paper layer, the back of which has repeating lines of tiny type that read "Tonga" and "The Friendly Islands."

Figure 6 shows the back of a Tongan 15-shilling Official airmail stamp (Scott CO7).

Many countries have used the back of the stamp to explain what is depicted on the front. The United States first did this in 1973 with a set of 10 stamps honoring postal workers (Scott 1489-98). The back printing shows the U.S. Postal Service eagle symbol and gives information about mail volume, equipment and other postal facts.

The practice of back printing has been used judiciously since then, including very effectively on the backs of the Celebrate the Century stamps of 1998-2000. The printing on the back of a 33¢ Harry S. Truman stamp from the series (Scott 3186d) is shown in Figure 7.

From 1984 to 1987, Great Britain used back printing on the low-value Christmas stamps that paid the second-class domestic rate commonly used for mailing Christmas cards. These stamps with the back print were sold at a 1-penny discount during certain dates.

And let's not forget those collectors and stamp dealers who write catalog numbers and values on the backs of stamps. I have an Estonian 1-sents Coat of Arms stamp upon the back of which some earlier collector wrote "91" and "2¢."

The stamp currently has the Scott catalog number 90 and a catalog value of 20¢, demonstrating that writing on the back of stamps is a practice that is not good for the stamps and has no lasting utility for the collector. Even if he got it right, catalog numbers do occasionally change and values are almost certain to.

If you feel compelled to note a catalog number and value, put the stamp into a glassine envelope and write on the glassine envelope instead.

Take care of the backs of your stamps just as you take care of the fronts.