Some of the larger nations have their own printing plants for stamps and paper money, while others depend upon the bank note firms of another nation. Among the printers who do much contract work are the American Bank Note Co., E. A. Wright Bank Note Co., Security Bank Note Co., Hamilton Bank Note Co., and H. L. Peckmore & Son, in the United States; Waterlow and Sons, Ltd., De La Rue & Co., Ltd., in England; J. Enschede & Sons, in the Netherlands; and Courvoisier, in Switzerland.

Most nations prefer the engraving process, since stamps are, in a sense, governmental securities or currency. It is true several large nations use other processes for economy or speed, but there is something in an engraved stamp which represents stability, and prevents counterfeiting.

A person qualified to engrave a design as minute as a stamp is at the top of the class, particularly one who can handle the frame, vignette and lettering. In this country, at least, each engraver devotes himself greatly to one of these fields.

The engraver uses a small piece of soft steel, known as the die, and, after tracing out the principal outlines of the design, proceeds to cut the subject into the die with a sharp tool. The depth and the thickness of the etched lines make for the heavy or light lines. It appears that the first part of the design to be engraved is the outline of the frame. From there the engraver works in, leaving the central vignette to the last. As he works he takes sample impressions to check his work, and these are known as die proofs, and as such are widely collected.

When the die is finished it is hardened and impressions are taken onto a soft heavy roll of steel, known as the transfer roll. Sometimes only one impression is made on the roll, and in other instances there may be ten or twelve. Then this transfer roll is also hardened, and work is commenced on the plate. This, too, is soft and highly polished steel. The impressions are laid down in regular rows vertically or horizontally-until the desired number of stamp subjects are on each plate. Then a plate number is added, if desired, or a special imprint such as the name uf the printing firm, and the whole plate is hardened.

In flat plate printing the plate is laid down on the press and inked, the ink sticking in the etched lines. The surplus ink is wiped off, paper is laid down and the whole thing run under a pressure roller or press, and the impression is made. Today, with speeded-up operations, the plate is curved into a semi-circle, and with a companion plate, is locked onto a roller. This is known as curved, or rotary, press.

Other methods used throughout the stamp world are lithography, typography, photogravure, heliogravure, and type-set.

Lithography has been used in conjunction with engraved frames in numerous instances. For examples there are the Dumas issue of Haiti, which was solely lithographed, and the Port-au-Prince issue of the same country, issued in iqso, which was a composite. The process, briefly, consists of printing from a stone, zinc or aluminum, upon which a design has been made by a soapy ink.

Typography is, of course, the printing from types set by hand or machine, and is, in effect, identical to that described as "type-set" designing. It might be noted also that typography represents the printing from raised type, where engraving is the reverse. Convenient examples of typography are the 1871 and 1878 issues of Guatemala, or the first issues of the Dominican Republic.

Type-set stamps are usually crudely done, and are frequently State stamps or locals. Some of the Confederate provisionals, the Hawaiian "Missionaries" and the early British Guiana issues were produced in that manner.

Heliogravure and photogravure are actually the same operation. The process, as the second term would imply, calls for the making of a photoengraved plate for printing in which there are no sharply cut lines, but rather faint, cuplike depressions (produced by photographing the copy through a fine screen and engraving the plate from the screened negative) with the high parts showing white when printed. This process has been used, for example, in the 1950 multicolored pictorial set of Guatemala, the 1935-7 postage and airmail issues of that country, several Mexican issues in about the same period, the King Edward VIII and King George VI issues of Great Britain, and many of the stamps of Switzerland.