The Nigerian Security Printing and Minting Company, abbreviated NSP&M, has with few exceptions since 1968 been the sole printer of Nigeria's postage stamps. The few exceptions since then have been as follows:
- The 1970 printings of the 2d and 4d wildlife definitives, which were printed by Enschede.
- The Stamp of Destiny issue of 1970, which was printed by Enschede.
- The Tenth Anniversary of Independence issue of 1970, which was printed by Enschede.
- The Racial Equality Year Issue of 1971, which was printed by Enschede.
- The All-Africa Trade Fair issue of 1972, which was printed by De La Rue.
- The Nigeria Drives Right Issue of 1972, which was printed by De La Rue.
- The All Nigeria Arts Festival Issue of 1972, which was printed by De La Rue.
- The 2004 re-prints of the wildlife definitives were printed by Cartor of France.
- The 2010 definitives which were lithographed by Kalamazoo Security Print Ltd., or Litho Superflux International Ltd. Lagos.
- All of the 1968 commemorative issues of Biafra, which were printed by the Lisbon Mint in Portugal.
- All of the 1969 commemorative issues of Biafra, which were printed in Italy.
The Printing Process
From 1968 until 1973, the primary printing process used was photogravure. The presses used for this process produced very high quality printing, on a par with the stamps of Great Britain. For some reason, which is not entirely clear, the use of this process ceased in 1973 and was replaced by lithography. Initially the quality was almost as good as the photogravure, but as time went on, especially into the 1980's, the print quality had gotten cruder and cruder. While this makes the stamps somewhat less appealing from a purely visual standpoint, it has resulted in stamps that are more interesting to collect, due to the large number of varieties that can be found on them.
There were some issues between 1968 and 1973 that were produced by the higher quality lithography as well:
- The 20th Anniversary of the World Health Organization (1968)
- The wedding of General Gowon (1969)
- The 5th Anniversary of the African Development Bank (1969)
All issues, except for the larger definitives of the 1969-72 are printed in sheets of 60. The horizontal format stamps are printed in sheets of 10 x 6, while the vertical format stamps are printed in sheets of 10 x 6. Most stamps have an imprint at the foot consisting of the designer's name on the left, and the initials NSP&M Co. Ltd. on the right. The size of the imprints varies on the 1969-72 definitives, with some of the smaller sizes being very scarce.
Sheets generally show the following marginal markings:
- The inscription "The Nigerian Security Printing and Minting Co. Ltd." appears in the lower right margin underneath the bottom four stamps in the case of the vertical format stamps, and the bottom three stamps in the case of the horizontal format stamps. On some horizontal format stamps, this inscription appears in the top right margin.
- In the bottom left margin contains the cylinder numbers - one for each colour used in printing. Generally, these are numbered 1A, 1B etc. On some sheets of horizontal format stamps, these numbers appear in the lower right side margin.
- In each corner of the sheet there is a cross, consisting of each colour printed on top of one another. The purpose of this was to enable the printer to assess whether or not the colours were in correct registration for the purposes of quality control.
- On the lower left side of the sheet, there is a series of small coloured dots resembling a set of traffic lights - one for each colour used in printing, On some sheets of the horizontal format stamps, these dots appear in the lower right margin underneath the second stamp from the bottom.
- A numeric value counter appears in the upper selvage above each stamp in the top row, totaling the face value in that column.
- A small coloured cross appears above and below the stamp of the 5th column in the upper and lower selvage, and boxed cross appears opposite the upper and lower stamps of the 6th column. These markings are found on the sheets of vertical format stamps. For the horizontal format stamps these markings are found opposite the 5th and 6th rows.
- The inscription "Total sheet value" and the total face value in kobo or Naira, appears in the upper right selvage above the top three stamps for the vertical format stamps, and above the top 2 stamps for the horizontal format stamps.
- On some sheets, I have seen invisible rectangular markings that fluoresce bright yellow green under UV light. I have seen these on the 1984 ICAO issue.
Paper and Gum Characteristics
There is considerable variation in the paper and gum employed to produce the stamps of this period:
- For the period from 1968 to 1972, and for the 1973 postage dues, the paper is a white, unsurfaced paper, that has been plate-glazed into a smooth finish. The paper generally shows very clear horizontal mesh, and the gum is smooth, shiny, with a satin sheen, and colourless. Under long-wave ultra violet light (UV), it is generally highly fluorescent, giving a bright bluish white glow.
- For a very brief period from January 2 to April 2, 1973, when the stamps are produced by photogravure, a thin, smooth chalk-surfaced paper was used. The gum is colourless and very shiny, with a glossy sheen. On used stamps, the back side is very smooth, and there is no visible mesh in the paper. This paper is also highly fluorescent, giving a bright bluish white reaction under UV, but also showing individual paper fibres.
- For the lithographed issues from April 1973 to the end of 1974, same thin, chalk-surfaced paper was used.
- For the first two commemorative issues of 1975, being the Inauguration of Telex Issue, and the International Women's Year Issue. a new thicker chalk surfaced paper was employed. The paper has no watermark, and under UV it appears dead, giving a deep purple reaction. The gum on this paper is a matte colourless PVA.
- Starting with the 1975 definitives and until 1992, a paper very similar to the thicker paper above is introduced. This paper is watermarked with the word "Nigeria" in continuous, repeating, wavy lines. Due to poor quality controls, it is commonly found either upright, or inverted on the horizontal format stamps; or sideways or sideways-inverted on the vertical format stamps. I have not seen reversed watermarks, sideways watermarks on horizontal format stamps, or upright watermarks on vertical format stamps. However, they may exist, and are probably quite rare if they do. Under UV light, the reactions given by this paper are quite varied. It can appear dead, giving a deep purple reaction. It can also give a fluorescent bluish white reaction of varying brightness. The reaction on the face and the back are often different as well, due to the way the chalk-coating reacts to the UV light versus the paper itself. The fluorescent reaction gets quite a bit duller around 1984, and the stamps often appear dead on the face, and low fluorescent on the back with hibrite fibres. This paper type is pretty well universal until 1992. The only issues that are printed on this paper that I know of after this are the Olymphilex Issue of 1992 and some values of the 1992 Barcelona Olympics. The gum on this paper is the same as above: a dull, matte colourless PVA.
- Starting with the 1992 Barcelona Olympic games, a thinner, unwatermarked, unsurfaced paper is introduced. The gum on this issue and two of the commemorative issues of 1992, being the 1992 World Health Day issue and the 1992 Institute of Tropical Agriculture Issue, is a brownish cream dextrine gum that has a satin sheen. Under UV light, this paper gives a bright bluish-white fluorescent reaction.
- Starting with the souvenir sheet for the 1992 Institute of Tropical Agriculture Issue, and the Maryam Babangida National Centre for Women's Development issue of 1992 and continuing until the present, the paper is a more medium thickness, unwatermarked, chalk surfaced paper. The gum on this paper is almost always a very shiny, colourless dextrine gum. Occasionally, one will find a matte PVA gum as well, and also a shinier PVA that has an semi-gloss sheen. Under UV light the reaction is generally a dull fluorescent to low fluorescent, being a greyish to dull bluish white for the issues up to 1995. Starting in 1995, with the 50th Anniversary of the UN issue, hibrite flecks that are very sparse and bright bluish white can be seen embedded in the paper under UV light. Starting in 1998 the paper often shows flocks that flouresce bright bluish white and bright orange red. The only issues that does not have these fluorescent flecks from this period is the Return to Democracy issue of 2000.
Order of Printing
Another characteristic that seems to affect the 1973-86 definitives, and to a lesser extent the 1984-93 definitives is the order in which the colours are printed. It would appear that for some stamps, printing required more than one pass through the press in order for all the colours to be printed. This opens up the possibility of obtaining the following varieties or errors:
- Errors of colour in which one or more colours are missing from the final design because the operator missed one of the required passes through the press.
- Differences in appearance of the stamps caused by a different ordering of the colours, so that some colours appear to be printed on top in certain sheets, and on the bottom in others.