The evolution of British stamps, as well as all postage stamps of the World, began on May 6, 1840, with the issue of the World's first two line engraved, adhesive, postage stamps.
The issue of postage stamps is a VERY SERIOUS undertaking. The postage stamps of any country represent that country to the rest of the nations of the World, no differently than a nation's government documents, bank notes, and coinage. The British were very meticulous in ensuring that their postage stamps were perfect, in every respect. During the 30 year period that the line engraved British stamps were printed and issued, they went through many different design and printing changes, in the government's goal of achieving ultimate perfection.
The Scott Catalog listings for the line engraved issues of Great Britain take up about 1 page of the catalog. The Stanley Gibbons Great Britain Specialised Catalogue listings for the line engraved issues take up the first 212 pages of the catalog. The link pages, in this section of the website, will feature a summary of these line engraved issues, based on the Scott Catalog listings, with occasional enhanced text descriptions based on the Stanley Gibbons catalog listings.
The line engraved stamps are the most complex area of British philately. As indicated by the Check Letters section below, one can easily determine what position a particular stamp comes from. But, which plate, out of the hundreds of plates used to print all of these stamps, is the particular stamp from? This is the question than can take a specialist an entire lifetime to answer. The printers didn't begin printing the plate numbers on the line engraved stamps until 1858, thus all the line engraved stamps issued from 1840 to 1857 have to be physically plated.
There are constant plate flaws on many of the line engraved British stamps that enable the collector to determine which plates some of them come from. These are described in great detail, in the Stanley Gibbons Great Britain Specialised Catalogue - Volume I.
But, this is not sufficient for the plating of all of these line engraved stamps. Unfortunately, most of the reference materials necessary for plating all the line engraved stamps have been out-of-print for decades. In some cases, the cost of the reference books can be more than the cost of the actual stamps! I have been able to locate a couple websites that address the plating of these stamps:
Here is what a complete sheet of the imperforate, line engraved One Penny stamps looks like .....
The One Penny and Two Pence line engraved stamps were printed in sheets of 240 subjects. The sheets had 20 horizontal rows, check lettered A - T, and 12 vertical columns, check lettered A - L. The first stamp in the sheet is check lettered AA, and the last stamp in the sheet is check lettered TL.
These tiny check letters in the bottom corners of each stamp indicate the location of that particular impression on the plate. In mathematical terminology, these letters are the x-y coordinates of the stamp's position in the printed sheet.
The lower-left-corner letter indicates the row the impression is on, and the lower-right-corner letter indicates the column the impression is located in.
For example, the block at the top of this page is lettered LD-LF and MD-MF. Thus, this block is from positions 136-138 and 148-150 on one of the Penny Black plates.