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T 0 D A Y
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Reference Page
Paper Types All of the following information is for your guidance in assisting you with your hobby by kind permission of Mr. R. Simpson. feel free to visit his web site at www.gbmachins.co.uk Most Machins, pre decimal and
decimal were printed on un-watermarked coated paper (uncoated errors do exist ).
Seven basic types have been used up to this time of the printing of the current
issues. These are listed as follows:
OCP: Is off white in to cream in colour and shows a dull reaction under the
ultra violet light. Bradbury and Wilkinson supplied their own paper for
the certain issues of the large recess printed stamps (i.e. £.s.d). This was
thinner than the original post office OCP paper. Stamps printed on this type of paper do not react to
ultra violet light and ink diffusion gives off a blurred design. Normally a thin
paper which will show the design of the stamp when viewed from the rear. Another experimental printing. A silicone coating was applied to certain strips of stamps (coils). These were sold through Post Office vending machines. The direct aim was to stop these stamps from sticking together whilst coiled in the machine. This coating tended to dull the surface of the stamps. GA : = Gum Arabic GA: This is a clear shiny gum and is very easy to detect when a light is shone across the surface. It shows a crazy paving effect when viewed under magnification, it was cracked by the printers deliberately because it was causing them difficulties, having a tendency to curl. Five types of gum have been used in the lifetime of the current Machin issues, not necessary in order these are listed below PVAl: Replacing gum Arabic it is slightly creamy white in colour and mottled in appearance. Shine a light across and it looks almost invisible. Harrison & Son and Enschede both added a dye to help distinguish the visibility, which brings us to type three (Dextrin). PVAD : This gum looks like PVA except a greenish tint has been added to make it more visible to the naked eye. According to some people the tint has disappeared on some of the later printings, but they have been assured that it is still technically a gum called dextrin. S.A (Acrylic): Introduced before layflat but sold only in the
Tyne Tees television area and philatelic counters. The first issues were
withdrawn from sale because the ink used to cancel them would not adhere to
the shiny surface. PVA (Layflat): This is still a PVA gum but has layflat qualities, the latest (except for acrylic) to be used by the Royal Mail. Recently introduced to stop the paper from curling in humid conditions. It looks creamy in colour, slightly darker darker than PVA or Dex and less shiny in appearance. Two types exist, the creamy type and a whiter version. It is believed that the whiter version is the same gum but with a thinner variation of paper. This was first tested on the 19p & 25P values issued in 1995.Up to date seven printing companies have been employed by the Royal Mail, some we have mentioned already elsewhere on the site. However here they all are, not necessary in order. The printers are Harrison & Son of High Wycome Photogravure & gravure Bradbury and Wilkinson & Co. Recess The House of Questa, South LondonLithography John Waddington Security Printers Lithography & gravure Walsall Security Print Lithography & gravure
De La Rue Gravure &( recess HV only) Sorting Stamps
Sorting Photogravure stamp from litho is not to difficult as
all photo stamps are printed by a series of tiny dots. Under magnification
they are easily seen especially in and around the margins, the Queens
portrait and the value tablet. The pattern of dots show up as uneven edges. These special markings were actually printed over the gum but are called under prints by collectors as not to confuse them with security overprints already catalogued previously. ( see overprints ) Several booklets were sold at discounted rates, to identify these the back of the stamps showed special markings, these markings were printed over the gum in a blue ink. The first booklet released was the Christmas discount booklet in 1982 the Dextrin gum had stars overprinted . There were three initial designs Type 1 (only used on the Christmas booklets ), type 2. and type 3 were both used on ordinary discount booklets.
The first, type 1 was a design of two stars overlapping, type 2 of a single star and type 3 was in the shape (or style) of the letter D. Type 3 was only used on PCP, the stars types were always on FCP. Left-over paper stocks of the single star type 2 were also used for the printing of the 12p values in sheets, these appeared as a multiple star laid out on the sheet, several parts of the overprint occur on the stamps similar to a multiple watermark Type 2 A, it is assumed that this was done by the printers to avoid problems of registration. Normally only mint copies of these stamps will show these overprints, with used stamps that are soaked and lifted from the backing paper the design will usually disappear with any traces of the original gum. Old phosphor : B Most early machins have this type of phosphor they consisted of either a centre band, two side bands, or a single side band. These were either green or blue in colour. New Phosphor : A A phosphor was brought into use in the mid 1980s, it is a variation of the phosphor used on the AOP paper issues (see phosphor coated paper ). The bands on these stamps fluoresce a little fainter than the previous printings, and are violet in colour. C Phosphor : This phosphor had a additive called cartax mixed with the phosphor ink. This in turn allowed the stamps to fluoresce a yellow green colour when viewed under long wave ultra violet light. This is also termed AY phosphor by some specialist groups. Early printings of this type were the 18p printed by Enschede in 1991. Several trials were carried out with various amounts of phosphor ink overprinted, this in turn resulted in several variations of yellow colour in the fluorescence. All these variations are catalogued and are all collectable. D & D2 Phosphor (Long wave afterglow or Novaglow) A trial printing D2 was released, this was termed nova glow by the printers in 1994 on the trial run of 38p stamps, again printed by Enschede. These stamps had a blue or light violet afterglow, this can be detected when viewed in a dark room under a long wave UV lamp, switch off the light after a few seconds for the desired effect. D phosphor was a intermediate blue phosphor without the afterglow. Some of the earlier stamps included a layer of varnish under the phosphor, this was either 2 mm or 4 mm wide ( more about varnish later ). Stamps with a D (blue fluorescence) have since been issued by all printers and now seems to be the norm on all current issues including Self adhesives. Questa, recent De La Rue stamps and other certain printings have the D2 aftergow. Width and length of Phosphors : As mentioned above all stamps of this type have either one or two bands running vertical from top to bottom of the perforations. Some have extra bands or no bands these were printed in error, and are highly collectable. First class stamps printed in sheets normally have 9 mm when split reverting into two 4.5 mm bands these are set each side of the stamp. The 10 mm10p stamp printed on the Chambon Press a exception to the rule having two 5 mm bands. Booklet stamps can also found to contain 8 mm & 4 mm bands. Second class stamps from sheets have one 4.5 mm centre band, or on more recent issues a 4 mm band. This can also be off-set of centre.
D & D2 Phosphor (Long wave afterglow or Novaglow) A trial printing D2 was released, this was termed nova glow by the printers in 1994 on the trial run of 38p stamps, again printed by Enschede. These stamps had a blue or light violet afterglow, this can be detected when viewed in a dark room under a long wave UV lamp, switch off the light after a few seconds for the desired effect. D phosphor was a intermediate blue phosphor without the afterglow. Some of the earlier stamps included a layer of varnish under the phosphor, this was either 2 mm or 4 mm wide ( more about varnish later ). Stamps with a D (blue fluorescence) have since been issued by all printers and now seems to be the norm on all current issues including Self adhesives. Questa, recent De La Rue stamps and other certain printings have the D2 aftergow. Width and length of Phosphors : As mentioned above all stamps of this type have either one or two bands running vertical from top to bottom of the perforations. Some have extra bands or no bands these were printed in error, and are highly collectable. First class stamps printed in sheets normally have 9 mm when split reverting into two 4.5 mm bands these are set each side of the stamp. The 10 mm10p stamp printed on the Chambon Press a exception to the rule having two 5 mm bands. Booklet stamps can also found to contain 8 mm & 4 mm bands. Second class stamps from sheets have one 4.5 mm centre band, or on more recent issues a 4 mm band. This can also be off-set of centre. Varnish under the bands As mentioned above, some of the stamps printed by Enschede have a varnish strip printed under the phosphor ink. These were applied to eradicate problems, with the paper being to absorbent, this in turn caused the phosphor to have a weak signal. Two widths of varnish were tried first a 4 mm varnish then later a 2 mm version. Both varieties are collectable although the 2 mm type is hard to distinguish as the layer tends to correspond with the inter stamp margins. To view these varnished bands they must be held up to the at a slight angle, the varnish seems a little lighter than the actual phosphor that has no vanish present.
Nearly 99% of variations come from booklet panes, they can consist of bands set either left or right, in different widths. Also variations of centre bands come in various widths including settings to the left or right of centre. Check for 8 mm & 4 mm bands, these are normally found on stamps from vending machine booklets. Phosphor bars: These are found on stamps from many booklet panes and consist of short bands bottom, short bands at the top, or short bands both top and bottom. Two band, centre band and side band varieties are catalogued, all are collectable. Inset Bands: Inset refers to bands that are inset from the perforations. Most of the inset bands are found from booklet pane material. Three types exist, these are inset left, inset right or inset from both left and right .( it should be noted that combinations of inset and short bands exist ) Notched Bands : These can be obtained from mixed value and prestige booklet panes, they consist of small notches in the top or bottom of the band. Four types are catalogued. Notched either top left, top right, bottom left or bottom right. It should also be noted that stamps exist with combinations of short, inset and notched bands. These can be very desirable stamps and will no doubt be rarities of the near future. Douglas G.A.Myall. Deegam publications has devised and written a reference system for these stamps, The Deegam SIN System. Douglas has kindly given his permission for these to be reproduced on site. They can be seen on the next page. Phosphor front and back : Phosphor is normally applied to the face of the stamp over the printed image, when phosphor is also found on the reverse of the stamp, this has been applied in error. Some experts claim that wet ink has been transferred from one sheet to another during the stacking process. Another reason has been suggested that a printing roller has picked up ink by mistake and deposited it to the rear of the sheets. Phosphor under ink : Some stamps have a milky appearance, this is caused by the phosphor being printed first, then the stamp image printed over the top. The best way to test for these variations is is to hold the stamp up to the light, the bands will appear milky and lighter than the none phosphor area.
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