United Kingdom Of Great Britain And Northern Ireland – Decimal "To Pay" Labels

In 1914, the United Kingdom of Great Britain and Ireland introduced adhesive labels indicating postage due on unpaid or underpaid mail. The amount due was equal to double the deficiency. The design included the words "POSTAGE DUE." In 1924, a half-crown value was added to the range. Whereas the design was almost the same as that for postage due labels with a face value of up to 1 s, these labels were inscribed "TO PAY." The initial design remained in use until 1970.

On 17 June 1970, the first decimal stamps were introduced. These were the high values of 10p (2s), 20p (4s), 50p (10s) and £1. In addition to recess-printed Machin postage stamps, four new to-pay labels with the same face values were introduced in a new design. Further values were added on Decimalisation Day, 15 February 1971.

The labels designed by Jeffery Matthews had two uses:
- Indicating postage due on unpaid or underpaid mail at twice the deficiency to the second-class mail rate; as such mail was automatically considered second-class mail;
- Indicating the customs and excise charges and from 1 April 1973 VAT charges on packages from abroad.

Accordingly, all values had the words "TO PAY" in the design. Lower values showed these words reading from bottom to top on the left side of the label. Higher values showed them upright at the bottom of the label. The Post Office designated these as "to pay labels." Being called labels may explain the absence of the Queen's portrait.

Technically, these labels reflected the changes to the concurrent Machin postage stamps. New designs by Sedley Place Design Limited ensued in 1982 and 1994.

The stamps issued on 17 June 1970 and 15 February 1971 were printed on the same coated paper as the pre-decimal Machin stamps: original coated paper (OCP). These had polyvinyl-alcohol gum, as did the Machin definitives at the time.



edit: correct name of Sedley Place Design Limited.

On 1 April 1973, the UK introduced a value added tax (VAT) on sales. The VAT replaced a purchase tax introduced during World War II. To-pay labels were used to indicate VAT due on goods received from abroad through the mail. Consequently, a stamp with a higher value than £1 was required. A £5-stamp was introduced on 2 April 1973.

At the time of its introduction, the Post Office had introduced a new paper with an optical brightening agent added to the coating: fluorescent coated paper (FCP). The £5 stamp was printed on this paper that still had polyvinyl-alcohol gum. During 1974 five further values were reprinted on the same paper.

A further change took place in 1974, when Harrison and Sons Limited added dextrin to its polyvinyl-alcohol gum. It added a blue dye to make it recognisable. The first to-pay label that was printed on the fluorescent coated paper with this gum type was the 20p value. The earliest known use of 2 May 1974 predates the earliest known use of that value on fluorescent coated paper with polyvinyl-alcohol gum that did not have the added dextrin. This may indicate that the paper with the ordinary polyvinyl-alcohol gum was either used in error or to use up remaining stock.

Two further values (7p and 11p) were issued only after the introduction of this gum.

In June 1980, the 10p and 20p stamps appeared printed on paper that had phosphor added to the coating: phosphor coated paper (PCP). This paper was used in error. Other stamps may exist on this paper but have not yet come to light.

In the 1950s, the moor water used in the production of stamp paper caused the paper to have a cream colour. In the early 1960s, the Post Office allowed paper makers to add optical brightening agents to the paper. This made the paper appear whiter. At the same time, it caused the paper to show a varying degree of fluorescent reaction to uv-light. In 1963, the Post Office conducted a trial with coated paper. The coating itself did not contain an optical brightening agent.

The coating of original coated paper (OCP) was like that used in the 1963 trial. It did not contain an optical brightening agent (OBA). When exposed to uv-light it turns blackish. At the same time, the paper itself did contain OBAs to varying degrees. Stamps on OCP may, therefore, show fluorescence from the back. As the gum can absorb some uv-light, mint stamps may show a somewhat reduced fluorescence from the back. Consequently, to check the paper type, the printed side should be irradiated with uv-light.

Fluorescent coated paper (FCP) has OBA added to the coating. Consequently, stamps printed on FCP-paper show fluorescence under UV-light from the front. As the amount of OBA varies, the reaction may be anything from noticeable, but not very strong, to "summer has arrived."

Phosphor coated paper (PCP) has phosphor added to the coating. After irradiation with (preferably short-wave) uv-light, the phosphor reaction will cause an afterglow. In the case of the two to-pay labels issued in 1980, this afterglow is greenish. The phosphor coated paper stamps have a finish that varies from dull (PCP1) to glossy (PCP2). This is not a difference in phosphor but a reaction to the phosphor coating. The two to-pay labels issued in 1980 have a glossy finish, being PCP2.


Fluorescence under a short-wave (Leuchtturm/Lighthouse) uv-lamp: OCP, FCP, and PCP2 (from left to right)


Fluorescence under a long-wave (Leuchtturm/Lighthouse) uv-lamp: OCP, FCP, and PCP2 (from left to right)

Fluorescence tends to be more visible under long-wave uv-light. Note the blackish appearance of the left (OCP) stamp in the latter picture.


Phosphorescence under a short-wave (Leuchtturm/Lighthouse) uv-lamp: OCP, FCP, and PCP2 (from left to right)


Phosphorescence under a long-wave (Leuchtturm/Lighthouse) uv-lamp: OCP, FCP, and PCP2 (from left to right)

British phosphors on decimal stamps up to 1992, generally, show a violet phosphorescent reaction to short-wave uv-light. These stamps show a greenish reaction that is strong after irradiation with both short-wave and long-wave uv-light. In the top picture, the OCP and FCP stamps are just about visible.


Paper fluorescence of the OCP stamp under a long-wave (Leuchtturm/Lighthouse) uv-lamp

Note the bright fluorescent reaction of the OCP stamp in the bottom picture, compared to that of the same stamp in the second picture on the left. The coating does not contain OBAs, but the paper itself does. The pictures were taken under the same circumstances.

NSK,

I've only just seen this thread. A good write up makes pedestrian stamps interesting.

Well done,


John

Agreed, great thread and contribution to the community and hobby. Thank you.
Don

The adhesive of British stamps, traditionally, was an organic gum known as gum Arabic. In 1968, Harrison and Sons Limited introduced a synthetic adhesive known as polyvinyl-alcohol gum. Polyvinyl alcohol gum has no colour. Soon, Harrison and Sons added a yellow-brown dye to the gum. This made it easier to identify the gummed side of the paper.

From 1973, Harrison and Sons Limited added dextrin to its polyvinyl-alcohol gum. This resulted in a thicker and harder gum. To make it possible to discern between the polyvinyl-alcohol gum and polyvinyl-alcohol gum with added dextrin, the printers added a bluish green dye to the gum. The difference is shown below for the 3p stamp.


Harrison and Sons Limited gums: polyvinyl-alcohol gum (left) polyvinyl-alcohol gum with added dextrin (right)

On 9 June 1982, a new design by Sedley Place Design Limited superseded the design by Jefferey Matthews. Like the original series, the new series consisted of labels showing large numerals and the words "TO PAY." The labels with a face value lower than 10p showed the words to the right of the numeral reading upward. Those with a face value of 10p and higher showed the words below the numerals.

After issuing the new design labels, Royal Mail changed the calculation of postage due on unfranked or under-franked mail items. The postage due was the shortfall in postage at the second-class mail rate with and added charge of 10p. Any amount due was rounded down to a penny.

The amounts due increased due to inflation and frequent use for levying value added tax on international packages. Amounts between £1 and £5 due required affixing multiple labels. To bridge the gap and reduce the number of labels required for such charges, Royal Mail introduced a £2-label.

Harrison and Sons Limited printed the new-design labels on its fluorescent coated paper. Collectors of Machin stamps will be familiar with the contemporary stamps with phosphor bars and phosphor-coated papers. The afterglow from the phosphor allowed for machine-sorting of first-class and second-class mail. As the mail would not pass through a sorting machine after applying the to-pay labels, there was no need to apply phosphor bars or phosphor coating. The adhesive used was its polyvinyl-alcohol gum with added dextrin.

After Royal Mail had replaced these labels by labels of yet another design, 2p-labels printed on advanced coated paper (ACP) were discovered. This paper had a coating which had a phosphor like the A-type phosphor used for applying phosphor bars mixed in. The paper was used for stamps pre-paying the basic tariff for first-class inland mail. A collector had bought some 2p-labels because he liked the colour of the labels and did not want to spend much money on the labels. These labels from a late printing had been printed on advanced coated paper.

Fluorescent coated paper has an optical brightening agent added to the paper coating. The coating is applied before printing the colour ink. As explained above, "fluorescent coated paper" refers to stamps that have a clay-coating with an added optical brightening agent. The optical brightening agent gives a bright response when irradiated with, especially, long-wave uv-light.

Both fluorescent coated paper and advanced coated paper show fluorescent reaction when irradiated by a long-wave uv-lamp. The advanced coated (also A-coated) paper shows a slightly weaker fluorescent reaction because the phosphor in the coating absorbs the uv-light.


Fluorescence under a Leuchtturm long-wave uv-lamp: FCP (left) and ACP (right)

To allow for machine-sorting of first-class and second-class mail, Royal Mail had printers apply phosphor bars over the coating. Usually, the phosphor bars were applied over the coloured ink. In the late 1970s, Harrison and Sons Limited started mixing phosphor into the paper coating as an alternative to applying phosphor bars over the coating. The phosphor used shows an afterglow when irradiated with short-wave uv-light.

There is a marked difference in the afterglow from fluorescent and advanced coated paper after irradiation with short-wave uv-light. The former does not contain any phosphor and has a very short-lived afterglow, if any. The phosphor in the advanced coated paper shows a strong afterglow.


Phosphorescence under a Leuchtturm short-wave uv-lamp: FCP (left) and ACP (right)

Harrison and Sons Limited printed the to-pay labels in double pane sheets. Each pane contained 10 rows of ten stamps. A gutter margin the width of a label separated the two panes. Harrison and Sons Limited had printed the to-pay labels of the 1970 design in sheets of 20 rows of ten labels.

The gutter margin between the panes were perforated through, giving rise to "gutter pairs." The gutter margin had the same size as ordinary stamps or to-pay labels. To prevent their use for forging stamps or labels, a line in the colour of the stamp was printed across the centre of the gutter margin.


1982, Great Britain, to-pay labels in gutter pairs