Lot 94 Canada #463iii 15c Dull Purple Greenland Mountains, 1967-1973 High Value Centennial Issue, A VFNH LL Plate 3 Block Of 4 On MF7-fl Paper With Dull PVA Gum, Violet Under UV

A VFNH LL plate 3 block of 4 of the 15c dull purple Greenland Mountains from the 1967-1973 High Value Centennial Issue on MF7-fl paper with dull PVA gum, violet under UV.

Unitrade values this at $6. The block offered here grades 80 as follows:

Centering/Margins: 50/70

Paper Freshness: 5/5

Colour: 5/5

Impression: 5/5

Absence of Visible Paper Flaws: 5/5

Perforations: 10/10

The Centennial issue stamps posess a complexity that extends far beyond either Unitrade's listings or Harris's listings. Both works give a good synopsis of the major groups of papers that can be found, as well as the basic gum and tagging differences. However within each of these attributes there are nuances that lend themselves out to specialized study, and in listing these blocks, we are tailoring our descriptions to the collector seeking advanced descriptons that address all of these.

The first attribute, and perhaps the most important is the paper. In addition to the basic fluorescence level, the paper itself can appear different colours under UV light. This becomes most significant when dealing with the dull papers, as the same basic fluorescence level can exist in 4 or 5 different colours under UV. We have included, with each of the listings the tables from the Keane and Hughes book on this issue as we find that they do the best job of capturing the differences that exist. The only departure we have made from their tables is in the assessment of fluorescence level. Keane and Hughes assign a level of 0 to all the dull papers and to our way of thinking this is not accurate. We follow the Irwin-Freeman 12 point scale in which 0 is dead, 1-2 is dull, 3-4 is LF, 5 is F, 6-7 is MF, 8-9 is HF and HB is 10-12. So, under this scale a lot of what K&H rate as 0 are actually a 1 or a 2, and this is how we describe them in our listings. Also, we note that the paper used for many of the PVA gum printings is horizontally ribbed on the higher values. We see two principal types pf paper for these printings, with one being quite thin and the other having a slightly plasticized quality to it, which often results in unpunched perfs, probably due to some additive in the paper that makes it difficult to punch through. The paper on the dex gum and spotty white gum printings can be found with distinct, but light vertical ribbing, which is mostly visible on the gum side.

The second attribute to expand on is the colour. No book that I am aware of other than Keane and Hughes does anything to look at shade differences, which is odd, because there are many, and they become even more pronounced when you study used stamps. We have described the shades, both as they appear in normal light, and when they appear completely different under UV, the colour under UV. Several of the inks on the HB paper printings actually appear black under UV.

The third attribute which receives less attention is of course the gum. While there are the basic PVA/Dex/Spotty White distinctions, within each of these there are subtypes too. For the dex gum, the original printings have a streaky and smooth gum that has what I would call a semi-gloss sheen, and a pale yellow cream colour. Later printings toward 1970 can be found with a lighter off white gum that is almost always smooth and even, with a highly glossy finish. The dex gum used on the HB paper printings issued in 1971 usually has a streaky appearance, with a satin sheen. Other late printings with dex gum can have a blotchy, mottled gum that looks almost as though someone dabbed it on with a sponge. Finally, some early printings from 1967 can be found with a dex gum that has a satin, instead of semi-gloss sheen. The spotty white gum, is actually a form of dex gum that has many of the qualities of PVA gum in that it is dead white, and less sensitive to moisture than the earlier dex gums. It varies in sheen and with how coarse or fine the streaks in the gum are. Some have, what can be described as a satin sheen, while others have more of an eggshell sheen. Lastly there is the PVA. The earlier PVA gum is relatively thick, quite white and has an eggshell sheen. Later PVA gum has a matte appearance and is relatively thin, with the stamp sometimes looking as thoough it lacks gum.

A fourth and final attribute is the tagging. Both the Winnipeg and Ottawa tags vary in terms of the intensity of the taggant applied to the stamp, with heavy tagging being almost brownish yellow in colour, moderate tagging beig a light yellowish cream colour and light tagging beinng almost unnoticeable. So, all our listings attempt to capture these nuances.

Please note that where DF paper is fluorescence level 1 on the Irwin-Freeman scale it is simply noted as "DF" or "DF-fl". Fluorescence level 2 is noted as "DF2" or "DF2-fl".