GB // Machin Technical Details // Philately

The Machin series

of postage stamps is the main definitive stamp series in the United Kingdom. It is a timeless classic in use since 5 June 1967 until today and thus the longest running stamp series all over the world.

Portrait photo of Arnold Machin,
O.B.E., R.A. (* 1911, † 1999),
British sculptor,
coin and stamp designer

ex MS #2743 or PSB #DX39

First issued Machin
pre-decimal
definitive stamp
on 5 June 1967

Photography of the
plaster cast of the
Queen's head

Pictorial label
ex PSB #DX39

First issued Machin
decimal
definitive stamp
on 15 February 1971

Non-Value Indicator (NVI) Machins

first appeared in 1989 for domestic mail in order to avoid printing of new stamps after each postal rate change. These stamps simply carry textual inscriptions »1^st« or »2^nd« to indicate class of service rather than a monetary value. In 1999, an »E« valued stamp was released for the letter rate to Europe. It has since introduced a number of variations including those for worldwide and European airmail use, for different weights, and for postcards.

SG #1452 - 22 Aug 1989
First NVI issue
Domestic letter rate
»1^st class« up to 20g
(19p)

SG #1451 - 22 Aug 1989
First NVI issue
Domestic letter rate
»2^nd class« up to 20g
(14p)

SG #1669 - 19 Jan 1999
NVI Postage for letters
up to 20g to Europe
(30p)

SG #2357a - 01 Apr 2004
postcard rate (43p)
to foreign destinations
ex booklet of four

On 23 March 2021 Royal Mail introduced the first NVI Machin definitive with a unique barcode added. Each barcoded stamp will have a digital twin and the two will be connected by the Royal Mail App. The unique barcodes will facilitate operational efficiencies, enable the introduction of added security features and pave the way for innovative services for the Royal Mail's customers. The barcodes match the stamp colour and sit alongside the main body of the stamp, separated by a simulated perforation line. The new barcode is an integral part of the stamp and must remain intact for the stamp to be valid. The new barcoded stamps enable you to watch and share an exclusive

»Shaun the Sheep«

Animated cartoon film
Poster Please

click ...

video via the »Data Matrix Code«

itself using the Royal Mail App. You or the recipient can watch the video just by scanning the stamp barcode using our App. More videos will be added over the coming months.


»Shaun the Sheep« comic character	23 March 2021 Second NVI issue	01 February 2022 First NVI issue	04 April 2022 Denomination issues	Special postmark data matrix code
»Shaun the Sheep« comic character	NVI & denomination Machin definitives with data matrix code (barcode)			Special postmark data matrix code
Royal Mail took the introduction of the »2D-barcode«, also known as »Data Matrix« or »QR-Code [Quick Response]«, for Machin definitives as an opportunity to redesign also the style of them, which has remained unchanged since 1967, and to change the colour scheme as well. The iconic Machin design has been retained in the new design and the colour scheme has been reversed to depict the effigy in colour against a white background. The barcode is printed in a matching colour alongside, separated by a simulated wavy-line die cut. The stamps are printed by Cartor Security Printers in gravure, in sheets of 25 on self-adhesive paper. The new size of the stamps is 39 mm x 30 mm, elliptical perforations 15x14½, U-shaped slits.

New style and colour of Machin definitives effective from 04 April 2022

Printers

UK-based International Security Printers

(ISP)

Former logo
ISP

Ltd,

Walsall

Former Walsall logo

Security Printers

(WSP)

Former logo
Walsall ISP

, and France-based

Cartor

Former logo
Cartor ISP

Security Printing have announced a rebranding to Cartor Security Printers (CSP), effective from 23 August 2021. The move, which reflects the way the company has grown and expanded in recent years, consolidates their existing brands to form a single

unified

New unified logo
CSP

identity. Printing of Royal Mail postage stamps continues.

International Security Printers (ISP) Ltd, Wolverhampton, West Midlands, England, founded in 2004.
All printing techniques (2004 to date)

In 2004 Walsall Security Printers (WSP) acquired the French Cartor Security Printing (CSP) and established ISP to head-up these both trading companies. The old brands Walsall and Cartor were officially no longer in use. However in philatelic circles the old names are still used to distinguish the location where stamps were printed (Walsall/England or Cartor/France), eg. .... printed by ISP (Walsall) or ... printed by ISP (Cartor).

De La Rue (DLR) Security Print, Basingstoke, Hampshire, England, founded in 1813.
Photogravure (1997 to date)

Walsall Security Printers (WSP) Ltd., Walsall, West Midlands, England, established in 1966 (original company founded 1894) and appointed as supplier to Royal Mail in 1987, started printing of 14p and 19p definitive stamps for booklets in 1989.
Lithography (1989 - 1997)
Photogravure (1997 - 2004)

Since 2004 International Security Printers (ISP) Ltd

Royal Joh. Enschedé en Zonen BV, Haarlem, Noord-Holland, Netherlands, founded 1703, started printing of 8p definitive stamps in 1979.
Photogravure (1979, 1991, 1993-1996, sporadically to date)
Lithography (1997, [1st])

Cartor Security Printing (CSP), La Loupe, Eure-et-Loir, France, formed in 1974, first GB stamp printing in 2005,
Modern stamp printing by Cartor.

Since 2004 International Security Printers (ISP) Ltd

Harrison & Sons Ltd., High Wycombe, Buckinghamshire, England, founded in 1750, first British stamp printing contract in 1881, followed by a major contract in 1911 for definitives and from 1934 until the 1980s virtually every British stamp came from Harrison. In 1997 Harrison was purchased by De La Rue, but continued Machin definitives printing until late 1998.
Photogravure (1952 - 1999)

The House of Questa, London, England. Formed in 1966, first British stamp printing contract in 1980. In 1984 Waddington acquired Questa, but the stamp printing continued under the name of Questa. In 1996 Questa was sold to MDC Canada followed by the acqisition and closure of Questa in 2002 by De La Rue.
Lithography (1980 - 1997)
Photogravure (1998 - 2002)

John Waddington Security Print Ltd., Leeds, West Yorkshire, England. Established in 1922, first British stamp printing contract for 4p definitives in 1980, but own stamp production was ceased in 1986 upon acquisition by Questa.
Lithography (1980 - 1986)

More information ...

Printing Methods
photo	Photogravure A recess printing process which uses photography to produce multiple images from a master.
litho	Lithography Planographic printing process (printing from a flat surface), based on the principle that oil and water do not mix, produces a flat image. The resulting lithographed stamps are muddy and lifeless, lacking both depth and contrast. Printing firms using this method include House of Questa, Waddington, and Walsall Security Printers.
	Photogravure stamp produced by the computerized EME process printed by De La Rue	Lithography stamp printed by House of Questa
	Please click on one of both images to enlarge for a better view of the printing methods' difference. Both 1st class Machin definitives come from the PSB No.DX22 »Profile on Print«.
EME eme/photo	Electro-Mechanically Engraved, introduced in 1997 due to computerization of the printing process. The »EME« gravure process uses a computer-controlled diamond stylus to engrave the image into the printing cylinder. The precision offered by this process allows a much sharper image of the Queen's bust than was possible with the old acid-etch process.

Paper Types
ACP	Advanced Coated Paper under short wave ultraviolet light it is very white in appearance and gives a strong afterglow.	FCP	Fluorescent Coated Paper a chalk coated paper with an added optical brightening agent. Slightly whiter appearance than OCP.
OCP	Original Coated Paper This is a chalk coated paper with little or no optical brightening agent. It is off-white or creamy and has a dull reaction to short-wave ultraviolet light. It was gradually replaced by FCP starting in 1971.	OFNP	OBA-Free Non-phosphorised Paper OBA - Optical Brightening Agents
OFPP	OBA-Free Phosphorised Paper OBA - Optical Brightening Agents	PCP PCP1 PCP2	Phosphor Coated Paper This is a chalk coated paper incorporating a phosphor activator during manufacture. It has a dull appearance, giving a weak afterglow under short-wave ultraviolet light. PCP1 PCP1 has a dull matt appearance and a strong afterglow. PCP2 PCP2 has a very shiny appearance and a strong afterglow.

Phosphor Tagging
blue phos	blue phosphorescent (slight violet afterglow when the UV light source is removed) Phosphor 'A' was brought into use in the mid 1980s on the ACP paper issues (strong violet afterglow when the UV light source is removed)
colour fluor	Fluoridated phosphor was brought into use in 1991 ['C'] and in 1994 ['D/D2'] 'C' - this phosphor had an additive called cartax mixed with the phosphor ink yellow/green (variations) fluorescent 'D' - blue fluorescent without afterglow 'D2' - blue/violet fluorescent with a blue or violet afterglow under long wave UV light
	phosphorescent blue	fluorescent yellow ['C']	fluorescent blue ['D']	fluorescent blue ['D2']	fluorescent violet ['D2']
Position and width of the phosphor bands	The width of the phosphor side bands (centered down the vertical perforation over two stamps) is 9.5 mm, which results in a 4.75 mm band on one or both vertical side(s) of a single stamp. The width of a single phosphor band applied down the centre of a single stamp is 4.5 mm. The purpose of the phosphor bands is to activate the Automatic Letter Facing Machins to sort the mail into first and second class. 2-band - 9.5mm left or right band - 4.75 mm centre band - 4.5 mm
	left band 4.75 mm	centre band 4.5 mm	right band 4.75 mm	2-band 9.5 mm (4.75 mm each side)
	The source of the above depicted pre-decimal Machin definitives is the predecessor stamp booklet (SG# ZP1 »Stamps for Cooks«) of the PSB series.

Security Features
Starting in 2009 Royal Mail introduced new security features for the Machin definitives to improve counterfeit protection and to prevent fraudulent sale and re-use of stamps already used for postage.
RM	Text pattern as iridescent overprint reading ROYALMAIL in wavy lines
SBP 1u SBP 1i	In 2016 Royal Mail introduced a new »Security Backing Paper« for all self-adhesive Machin definitives (counter sheets, booklets). The backing paper shows an overprint under the silicone laminate. The overprint reads »ROYALMAIL« in all greyish capital letters in alternate printing of large and small size in a diagonal pattern across the backing paper.
	Type 1u - lettering upright Large size Small size Click image to enlarge		Type 1i - lettering inverted Large size Small size (incorrect usage of SBP) Click image to enlarge
SBP 2u SBP 2i	In 2017 things became a little bit more complicated. Royal Mail had ordered a change to the security printing on the backing paper of self-adhesive stamps so that the paper could be used inverted without producing a variety. This would be achieved by printing alternate pairs of lines upside-down (Type 2u). If the paper had to be re-rolled, it would still be up the right way - but if that paper is used inverted! again a pattern variety will be produced. (Type 2i).
	Type 2u - alternate lettering Large/small size upright Large size Small size Large/small inverted Large size size Small size Click image to enlarge		Type 2i - alternate lettering Large size upright Small size inverted Large size inverted Small size upright (incorrect usage of SBP) Click image to enlarge
U [1 2 2a 3]	U-shaped slits The slits are designed to inhibit the removal of these stamps from the paper. Unfortunately this causes problems to collectors of used Machin definitives, because the slits damage the stamps when soaked.
	Type 1 cuts at left and right printed by De La Rue	Type 2 cuts at left, right, wide at top, bottom printed by Walsall	Type 2a cuts at left, right, narrow at top, bottom printed by De La Rue	Type 3 cuts at left, right and bottom missing at top (50p from PSB DX50) printed by Walsall
	Display images

MxIL	Source Code Also in 2009 1st/2nd class NVIs appeared with a code denoting the source of the stamp. This code is "hidden" in the curvy ROYAL MAIL pattern, located above the diadem. The source code replaces the letter "A" of the word MAIL and became a standard for all new or reprinted Machin definitive issues from 2010 on.
	Source codes - type of source in brackets ()
	MBIL (Business sheet)	MFIL (Booklet of Four stamps)	MMIL (Miniature sheet)
	MCIL (Booklet of 2 Commemoratives and 4 Machin NVIs)	MSIL (Booklet of Six stamps)	MPIL (Prestige stamp book)
	MRIL (Rolls [coils])	MTIL (Booklet of Twelve stamps)	MAIL (no code) (Counter sheet)
	Display images
	Exceptions: Source code is "hidden" in the word ROYAL instead of the word MAIL, only 1st/2nd Large NVIs issued in 2009.
	FOYAL (Booklet of Four stamps)	ROYBL (Business sheet)	ROYAL (no code) (Counter sheet)
	Display images
	Exceptions: The text pattern overprint of the Machin NVIs issued on 6 February 2012 read DIAMOND JUBILEE The 1st class NVIs have the letter "O" of the word DIAMOND (just below the back of the crown) replaced by the corresponding source code. The 1st class Large NVIs have the letter "E" of the word JUBILEE replaced by the corresponding source code.
	DIAMBND (Business sheet)	S T C M P, no code (other possible source codes)
	JUBILFE (Booklet of Four stamps)	B, no code (other possible source codes)
	Display images
MAyy \| MyyL	Year Code In 2009 all Machin NVIs and the self-adhesive 50p stamp from PSB SG# DX50 were issued with a code denoting the production year of the stamp. This code is "hidden" in the text pattern overprint. The last two digits of the year of printing replaces the letters "IL" or "AI" of the word MAIL/MAIL and became a standard for all new or reprinted Machin definitive issues from 2011 on, apart from very few exceptions (e.g. 2012 Diamon Jubilee NVIs do not have a year code).
	Display images

Perforation Measurement (The gauge of a perforation is the number of holes in a length of 2 cm)
perf 15	Standard perforation is 15 x 14 (actually 14¾ x 14¼)	15 teeth along top edge
perf 14	Perforation 14 x 14 (actually 13¾ x 14¼) by Walsall, or (actually 13½ x 14¼) by Questa and Waddington	14 teeth along top edge
	The vast majority of Machins are perforated 15x14 but some of them also exist with both perforation varieties, mainly regionals.
[perf 13]	Perforation 12¾ x 13 was caused by the use of an incorrect perforation comb by Walsall, on stamps NVI 1st* bright orange-red*, SG# 1516c ex booklet SG# HB3a, Okt 1990	13 teeth along top edge Please click
el perf 15 el perf 14	Brought into use on 6 April 1993 a three hole ellipse on each vertical edge of the stamp was added as a security feature to prevent re-use and deter forgery. Elliptical perforation 15 x 14 (actually 14¾ x 14¼) Elliptical perforation 14 x 14 (actually 13¾ x 14¼ or 13½ x 14¼) Since then, two types of elliptical holes have been identified: narrow at top and bottom, with rounded sides (eR[ugby ball shape]), De La Rue (and others) printings wide at top and bottom, with almost straight sides (eS[ausage shape]), House of Questa Printings Identifying these two types of elliptical perforations on single stamps is rather difficult, pairs or blocks make it easier.
	Elliptical perforation at left: Type eR (»Rugby ball« shape) at right: Type eS (»Sausage« shape) SG# U3012b (5p) // U3017 (50p) 19 Sep 2013 // ex PSB »Merchant Navy« SG# DY8 misplaced elliptical perforations at top of sides of stamp - printed by Enschedé	SG# W72 //23 July 1996 // 20p // bt green // Wales Elliptical perforation - Type eS printed by House of Questa SG# Y1722 // 27 March 2007 // 48p // Rhododendron Elliptical perforation - Type eR printed by De La Rue
(el) dc	(Elliptical) die-cut 14 x 15 or 14½ x 14, self-adhesive stamps, in PSBs the first self-adhesive stamps appeared in #DX22 »Profile on Print«

United Kingdom of Great Britain and Northern Ireland
Union flag which represents England, Scotland and Northern Ireland	England Cross of St. George	Wales - Cymru Welsh Dragon	Scotland Cross of St. Andrew (called saltire)	Northern Ireland Tuaisceart Éireann Norlin Airlann Cross of St. Patrick	Northern Ireland Ulster banner Meirge Uladh (unofficially)
Please click on flags to learn more ...

The following five printing methods were introduced in PSB No.DX22 »Profile on Print«
EME/Photogravure by De La Rue Lithography by House of Questa Lithography embossed by Walsall Intaglio engraved (recess) by Enschedé Letterpress typographed by Harrison Please click on images (right) to enlarge	Lithography embossed »The Invisible Stamp«	Intaglio (recess) engraved	Letterpress typographed

Gum Types
wag	water activated gum	GA	Gum Arabic, white shiny, until the late 1960s
PVA	Polyvinyl Alcohol, matt shiny since 1993 yellowish or bluish-green or white matt-shiny	PVAD or Dex	Polyvinyl Alcohol + Dextrine additive Dextrine Additive (bluish-green gum)
SA	Self-Adhesive gum (Acrylic)	PVAI	Polyvinyl Alcohol Layflat (first tested on the 19p/25P values issued in 1995)

Common Abbreviations
SG#	Stanley Gibbons catalogue numbers referring to Great Britain Concise Stamp Catalogue 2021	ZPn DXn DYn	SG »Prestige Stamp Book« numbers
PSB	Prestige Stamp Book	NVI	Non Value Indicators, first appearance of non- denominated Machins in 1989 (1st, 2nd, E[urope, 1999], Worldwide, etc.)
MD	Machin Definitives	MRD	Machin Regional Definitives
CD	Country Definitives	SS	Special (commemorative) Stamps

Useful References
	Royal Mail Stamps	Royal Mail Postmark Bulletin
	Burgess Complete Machin Stamp Catalogue 2022	Stanley Gibbons Catalogues
	»Deegam« (†) Machin Handbook	Norvic Philatelics Blog
	Machin database created by Robin Harris	Collect GB Stamps
	Machin Timeline	Basic Machins (printable pages)

Contents
Printers	Printing Methods	Paper Types	Phosphor Tagging	Security Features
Perforation	Gum Types	Common Abbreviations	Useful References	Prestige Stamp Books