The 8c Slate Parliamentary Library Stamp of the 1967-1973 Centennial Issue Part Three

Today is the third of four posts dealing with the last of the low values of this issue: the 8c Parliamentary Library stamp. In this week's post, I will be looking at the printings of the sheet stamps that were Ottawa tagged.   According to Unitrade, the sheet stamps were first issued at the same time as the Winnipeg tagged stamps, on December 30, 1971, using the then unstable OP-4 tagging compound. This compound migrated both through the stamps and onto any porous material they came into contact with. The result was that the tagging bars faded to the point that they were useless to the mail sorting machines, so that by late 1972, the taggant compound was replaced by a more stable OP-2 compound. The new printings with the more stable OP-2 tagging were issued in 1973 between April and July, well into the period covered by the new Caricature issue that replaced this one, but before the release of the low values of that set.

The CBN coil stamps with OP-2 tagging were issued at the same time as the untagged stamps, on December 30, 1971.

Unitrade lists two varieties of the OP-4 tagging, one with dextrose gum and the other with PVA and lists three varieties of the OP-2 tagging, all with PVA gum. There is also a scratch on the forehead variety listed for the OP-2 tagged stamps. Interestingly, there is no listing for the extra spire variety on these stamps, even though they likely should exist with OP-4 tagging. No fewer than five varieties are now listed for the coil stamps, in addition to two varieties of imperforate pairs. This is far more coverage than was afforded these stamps even a few years ago. So, more and more discoveries are being made for this set all the time.

The remainder of this post will now go over the printings of the sheet stamps in more detail. I will deal with the coil stamps in next week's post, which will also discuss the booklet stamps.

The OP-4 Tagged Sheet Stamps - Unitrade #544pi and 544pxix

Paper Characteristics Other Than Fluorescence

I have found three types of paper used to print these stamps, ignoring the fluorescent properties:

1. A cream coloured, horizontal wove paper, that shows clear vertical ribbing on the printing face. The paper is very lightly coated on the surface, as can be seen under magnification. When the paper is held up to a strong back light, a very strong vertical mesh pattern can be seen. 
2. A cream coloured, horizontal wove paper similar to that above, but with less obvious ribbing on the surface. When held up to strong back light, a clear vetical mesh pattern is still visible, but is less prominent than in the first paper type above. This paper is also lightly coated on the printing surface. 
3. A whiter, horizontal wove paper, that shows clear vertical ribbing as the first type above.  The paper is very lightly coated on the surface, as can be seen under magnification. When the paper is held up to a strong back light, a very strong vertical mesh pattern can be seen.

The whiter paper is shown by the block on the left, while the cream paper is shown by the block on the right.

Paper Fluorescence

Unitrade lists this stamp as existing either on non-fluorescent paper for those printings with dextrose gum, and on high fluorescent flecked paper for those printings with PVA gum. I do not have any examples of the PVA gum printing to work with in preparing this post, so unfortunately I cannot comment on the paper fluorescence of those printings. However, I have found no fewer than 6 subtle varieties of dull fluorescent paper, one of which is very close to being truly non-fluorescent. Unitrade calls this non-fluorescent, but in reality it is really different variations of dull fluorescent and dull fluorescent flecked paper. The scans below show the different types:




The block on the right is the dull fluorescent greyish paper, containing no fluorescent fibres. The paper of the block on the left is dull fluorescent greyish white with no fluorescent fibres.



The block on the left is dull fluorescent bluish white, with no fluorescent fibres, while the block on the right is dull fluorescent greyish, also with no visible fluorescent fibres in the paper.



The block on the left is non-fluorescent greyish under the UV light, with very few low fluorescent fibres visible in the paper. The block on the right is dull fluorescent ivory grey, also containing very few low fluorescent fibres.


The block on the left is the dull fluorescent greyish white paper containing very few low fluorescent fibres. The block on the right is the same non-fluorescent greyish paper that was shown in the previous picture.


Shades

I have only found one shade of ink on these stamps, though all of the stamps and blocks that I have in my possession are the dextrose gum varieties. The shade is a deep bluish slate that has a fairly good balance of blue and slate. The shade is shown in the scan of the block shown below:


Gum

The dextrose gum found on these printings exists in three of the four types that I have previously discussed: high gloss, semi gloss and semi-smooth. I have not yet seen an example of the crackly gum on these stamps. The pictures below show all three types of gum:


The high gloss gum is shown in the bottom block in the picture above, while the semi-gloss gum is shown in the top block.

The picture above shows the semi-smooth gum.

I haven't seen the PVA gum on the one printing that is listed by Unitrade to exist with PVA gum, being the high fluorescent flecked paper. However, as I will note in the next section dealing with the OP-2 tagging, all of the PVA gum that I have seen on these stamps has the same appearance: a cream coloured, smooth PVA gum with a satin sheen.


Perforation

The perforation on these stamps remains at comb 12.5 x 12, following the exact same configuration as the earlier printings, in which the side margins of the sheets are fully perforated through, but only a single extension hole appears in the top and bottom sheet margins. I have not found any variation in the gauge, or configuration of the perforation.

Tagging

The OP-4 tagging was applied in 4 mm wide bands that ran down the vertical perforations of each column in the sheets. The spacing between the tagging bars is 20 mm in the horizontal direction. In all cases that I have examined the taggant has become coloured by the printing ink, so that the tagging bars appear a very light azure colour in normal light, as shown by the following scan:


The block at upper left is an example of tagging that has almost completely faded. The upper right shows an example of 4 mm OP-4 tagging that is full strength. The block at the bottom shows tagging that has undergone slight fading. Generally, the brighter the tagging the closer to yellow the colour is and the further from green it is. 

Plate Flaws

Curiously, there are no listed plate flaws on this stamp even though it is more than likely that the PVA gum printings were from plate 4, and it is on plate 4 that we see the extra spire variety. Of course, many of these stamps can be found with the over 75 constant cylinder varieties that can be found on these stamps.

Bringing it All Together

All of these stamps were trimmed before distribution to the post offices, so there are no plate blocks to collect - only blank corners, of which there are up to 12 different collectible positions, depending on the width of the selvage tabs. I have noted three different types of paper, each of which could exist in at least six different grades of fluorescence, and each of which can exist with three different types of dextrose gum. Assuming that only one variety of the PVA gum printing can exist, there could be up to 3 x 6 x 3 = 54 different varieties of the dextrose gum stamps, and up to 54 x 12 = 648 collectible corner blocks.

The OP-2 Tagged Sheet Stamps - Unitrade #544piv, 544pv, 544pvii and 544pviii

Paper Characteristics Other Than Fluorescence

Unitrade lists this stamp as existing on smooth paper and vertically ribbed paper. The smooth papers are listed for both listed varieties of fluorescence, while the ribbed paper is only listed as existing on the high fluorescent paper.

The ribbed paper found on these printings is very strongly ribbed on the face, with the vertical ridges being very obvious to the naked eye. The paper is horizontal wove and is very lightly coated on the printing surface, as can be seen under magnification. The paper is a light cream colour when viewed against a stark white background. When held up and viewed against strong back lighting, the vertical mesh pattern is highly visible in the paper.

The paper of the plate 5 and 6 printings has a smooth appearance, with no ribbing visible, is lightly coated on the printing surface, has a slightly bluish appearance from the printing ink used to print the stamps and shows a clear horizontal mesh pattern when viewed against strong back lighting. The paper from plate 7 is much the same, except for the colour: plate 7 paper is a definite light cream colour, whereas plate 6 and plate 5 paper is white with a bluish undertone.

The scan below shows the difference in appearance between the cream paper of plate 7, versus the bluish-greyish white paper of plates 5 and 6, when viewed against a bright white background:


Paper Fluorescence

Unitrade now lists two levels of fluorescence for these printings:

1. High fluorescent.
2. Low fluorescent flecked with fluorescent fibres.

Shades

On these stamps each plate seems to have resulted in stamps that are a distinctly different shade of slate. The shades seem to be uniform within each of plates 5, 6 and 7, and this uniformity may well be an aid to identifying singles and blank blocks by plate. The plate 5 printings seem to  be a pale greyish slate shade that contains much less blue to the point that it appears more greyish than bluish. The scan below shows a side-by side comparison of this shade next to the deep bluish slate of the OP-4 printing:

As you can see, the difference is quite marked. The pale greyish slate is shown on the left, while the deep bluish slate is shown on the right.

The stamps from plate 6 are a deeper version of the greyish slate shade, which clearly contains more black and grey and less blue. It is shown next to a plate 5 block to illustrate the difference in the shades:

The deep slate is shown on the left, while the pale greyish slate is shown on the right. In this scan, the pale greyish slate appears quite bluish as well.

The printings from plate 7 are a clear slate greenish blue, which contains more blue and green than it does black. It is a very distinct shade, as the following comparison scan shows:



Gum

The gum found on all of these stamps is a smooth, white PVA gum with a satin sheen.

Perforation

The perforation on these stamps remains at comb 12.5 x 12, following the exact same configuration as the earlier printings, in which the side margins of the sheets are fully perforated through, but only a single extension hole appears in the top and bottom sheet margins. I have not found any variation in the gauge, or configuration of the perforation. However, there is one important difference: the perforations have been made using more than one strike of the comb perforator. This is apparent from looking at the side perforations. Here, we can see an uneven spacing and misalignment of the horizontal perforations where one comb strike ends and the other begins. This can be seen in the scan below:


Tagging

The tagging bars are 3 mm wide on these printings, rather than 4 mm. The horizontal spacing between the tagging bars is 21 mm rather than 20 mm. On the plate 5 and 6 printings, the bands have often picked up some of the printing ink and appear light azure on the stamps and blocks. Later printings from plate 7 have not been affected by this discolouration on any of the stamps and blocks that I have examined. On these printings, the bands are almost invisible, except for a shiny area on the paper where the tagging bars are. The scan below shows these differences.


Rose lists three tagging errors for each of the main leels of fluorescence: high, medium and low fluorescent. The three errors listed for each are of course:

1. G1aC - 1 central tag bar
2. G1aR - 1 tagging bar at right
3. G1aL - 1 tagging bar at left

Plate Flaws 

These stamps are printed from plates 5, 6 and 7, so there is no "extra spire" flaw known on them. Unitrade does list a scratch on the forehead variety. It appears as two horizontal lines at the upper left of the Queen's forehead. Unfortunately, I do not have an example to illustrate at the present time, but will add an image as one becomes available. As is the case with the OP-4 tagged printings, these stamps can be found with the over 75 constant cylinder varieties that can be found on these stamps.

Bringing it All Together

Unlike the earlier OP-4 printings, these stamps were not all trimmed before distribution to the post offices, so that it is possible to collect plate 5, 6 and 7 blocks, as well as blank corners, of which there are up to 12 different collectible positions, depending on the width of the selvage tabs. So:

1. For the vertically ribbed papers, I have identified 5 levels of fluorescence and three possible tagging errors, for a total of four different types of tagging. So for these papers there are potentially 5 x 4 = 20 collectible stamps and 20 x 12 = 240 collectible corner blocks.
2. For the plate 5 printings, I have only one type of each attribute except for the tagging and therefore potentially 4 collectible stamps, 16 plate blocks and 48 blank corner blocks.
3. For the plate 6 printings I have found two different varieties of fluorescence, but otherwise all other attributes would appear to exist in only one variety. So there could be as many as 4 collectible stamps, 16 collectible plate blocks and 48 collectible corner blocks. 
4. For the plate 7 printings I have found three different varieties of fluorescence, but otherwise all other attributes would appear to exist in only one variety. So there could be as many as 3 x 4 = 12 collectible stamps, 48 collectible plate blocks and 12 x 12 = 144 collectible corner blocks.