The 4d vermilion of 1969 replaced the dark-colored 4d of the original 1967 issue.

The Machin series of postage stamps are the common definitive stamps of the United Kingdom. Designed by Arnold Machin, they consist of simply a profile of Queen Elizabeth II and a denomination, almost always in a single colour. They were first issued on 5 May 1967, and proved quite popular; as of 2006 they continue in heavy use. Image File history File links Machind. ... Image File history File links Machind. ... A selection of Hong Kong postage stamps A postage stamp is evidence of pre-paying a fee for postal services. ... A definitive postage stamp is a regular issue stamp that is part of a definitive issue or definitive series consisting of a range of denominations sufficient to cover all postal rates usefully. ... Arnold Machin (30 September 1911 _ 9 March 1999) was a British artist, sculptor, coin and stamp designer. ... Elizabeth II (Elizabeth Alexandra Mary Windsor; born 21 April 1926) is Queen of sixteen sovereign states, holding each crown and title equally. ... May 5 is the 125th day of the year in the Gregorian Calendar (126th in leap years). ... 1967 (MCMLXVII) was a common year starting on Sunday of the Gregorian calendar (the link is to a full 1967 calendar). ... 2006 is a common year starting on Sunday of the Gregorian calendar. ...

From the philatelic point of view, the "Machins" are far more complex than the simple design might suggest, with hundreds of varieties known. Since the first stamps were issued pre-decimalisation, they exist in both old and new currencies. As postal rates changed, new denominations became necessary; the design has been adjusted periodically, for instance to use a gradient shade in the background; perforations have been changed; and so forth. In addition, regional stamps add regions' symbols to the basic design. Close examination of the Penny Red, left, reveals a 148 in the margin, indicating that it was printed with plate #148. ... Decimalisation (or Decimalization) refers to any process of converting from traditional units, usually of money, to a decimal system. ...

Initially the stamps were produced by Harrison & Sons using photogravure, with the high-value designs being larger and engraved. Starting around 1980, The House of Questa and Waddingtons Security Print also took up Machin printing in order to keep up with demand, producing their versions via lithography. Photogravure is a type of intaglio printing process used for reproducing monochromatic (black and white) images. ... Engraving is the practice of incising a design onto a hard, flat surface, by cutting grooves into it. ... Negative lithography stone and positive print of a map of Munich. ...

Apart from the many values of normal-sized stamps, there have been two different formats used for "high-value" definitives. In 1969 a square format was used to issue stamps of 2/6, 5/-, 10/- and £1 face value, and was used again in 1970 for the decimal currency values of 10p, 20p, 50p and £1 (the £1 stamp's value lettering being in a different font from the pre-decimal stamp). In 1977 a large portrait format was used for £1, £2, and £5 stamps, and also at various times between 1983 and 1987 for the odd values of £1.30, £1.33, £1.41, £1.50 and £1.60. These values were withdrawn after the introduction of the "Castles" high-value stamps of 1988.

In 1989, as a workaround to the problem of fast-changing rates, "non-value indicated" (NVI) Machins used textual inscriptions "1ST" and "2ND" to indicate class of service rather than a numeric value. The following year saw the first commemorative adaptation of the design, with the classic William Wyon profile of Queen Victoria appearing behind and to the left of Elizabeth, marking 150 years of British stamps. Non-denominated postage is postage that does not lose its value after a postal rate increase. ... William Wyon (1795—1851) was official chief engraver at the Royal Mint from 1828 until his death. ... Victoria (Alexandrina Victoria; 24 May 1819 – 22 January 1901) was the Queen of the United Kingdom of Great Britain and Ireland from 20 June 1837, and the first Empress of India from 1 May 1876, until her death on 22 January 1901. ...

1993 saw the introduction of both self-adhesives and elliptical perforations, the latter as a security measure. Self-adhesive stamps were first issued in such tropical climates as Sierra Leone and Tonga in an attempt to avoid the sticking-together tendencies traditional water-activated stamps had in humid conditions. ...

Colours

The most striking aspect of the Machins is the rainbow of colours. Since the designs are all identical (or nearly so), it was critical that each denomination be produced in an easily-distinguished colour. Worse, the likelihood of rate changes meant that additional colours would be necessary, since old stamps were still valid and could appear on mail.

The initial palette of 14 colours was chosen after extensive testing. While most were solid colours, the 1/6d and 1/9d used different colours for effigy and denomination, while the 10d and 1/- had backgrounds that varied from darker on the left side to lighter on the right. The dark olive-brown shade of the 4d value, the most often-used stamp of the time, was personally selected by the Queen as being the available colour most reminiscent of the Penny Black. However, in practice this proved difficult to distinguish from the 5d's dark blue, automated machinery could not always see the phosphor bands on the stamps, and even football pool organizers complained that it was too hard to read the date and time of cancellations. In 1969, the 4d value was changed to vermilion, which in turn required a colour change for the 8d, which was reissued in "eggshell blue". The Penny Black, partially obscured by a red cancellation. ... Pool has several meanings: A planted garden pool at Mission San Juan Capistrano It is any of several games similar to billiards, distinguished by using a table that has one pocket at each corner and one in the middle of each of the two longer sides. ... A machine cancellation On mail, a cancellation (or cancel for short) is a postal marking applied to a postage stamp or postal stationery indicating that the item has been used. ... Vermilion, also spelled vermillion, when found naturally-occurring, is an opaque reddish orange pigment, used since antiquity, originally derived from the powdered mineral cinnabar. ...

In preparation for decimalisation in 1971, the BPO prepared a new palette of colors, enlisting the Applied Psychology Unit of the Cambridge University to test individuals' abilities to quickly identify colours. The results pruned a selection of 25 down to the 14 used for the decimal stamps. The Medical Research Councils Cognition and Brain Sciences Unit is a branch of the larger Medical Research Council. ... The University of Cambridge is the second-oldest university in the English-speaking world, with one of the most selective sets of entry requirements in the United Kingdom. ...

In subsequent years, rate changes required new denominations, and in order to make colours available, older stamps had to be withdrawn. For instance, the 11p rose of 1976 was withdrawn in 1980, and the colour reused in 1983 for a 23p stamp. A re-introduced denomination could not normally get its old colour back though; the light green 17p of 1980 was withdrawn in 1981, reissued in steel blue in 1983, withdrawn 1986, and reappeared yet again in 1990, this time in dark blue. Steel Blue is a shade of blue. ...

In 1983, Aubrey Walker of the Royal Mail's R&D department proposed a fixed assignment of colours to rates, on the theory that the classes of service changed much less frequently than rates. This still did not solve the problem of clerks detecting usage of old stamps with lower rates - they would have had to read the denomination rather than just glance at the colour - and so a system of "light" and "dark" colours was suggested, the two variants alternating at each rate change. Artist Jeffery Matthews was then hired to develop the actual colours, and in 1985 presented eight pairs totalling 16 colours. The colour pairing idea turned out to be unworkable, but the colours were adopted, and in 1988 Matthews developed another 15 as rates continued to churn.

References

• Douglas G A Myall, The Complete Deegam Machin Handbook, 3rd ed. (D.G.A. Myall, 2003). At 1,272 pages, the only Machin Source Book in existence. Everything there is to know.....and more!
• David Alderfer and Larry Rosenblum, "Colors of Machins were carefully considered", Linn's Stamp News, July 8, 1996
• Larry Rosenblum, "Machins rainbow barely keeps up with needs", Linn's Stamp News, August 12, 1996

Linns Stamp News is the largest weekly newspaper for stamp collectors, boasting a paid circulation of nearly 45,000 (as of 2003). ... July 8 is the 189th day of the year (190th in leap years) in the Gregorian Calendar, with 176 days remaining. ... 1996 (MCMXCVI) was a leap year starting on Monday of the Gregorian calendar, and was designated the International Year for the Eradication of Poverty. ... Linns Stamp News is the largest weekly newspaper for stamp collectors, boasting a paid circulation of nearly 45,000 (as of 2003). ... August 12 is the 224th day of the year (225th in leap years) in the Gregorian Calendar. ... 1996 (MCMXCVI) was a leap year starting on Monday of the Gregorian calendar, and was designated the International Year for the Eradication of Poverty. ...

External links

• A comprehensive Machin site