Printing Inks Used On The 1967-1973 Centennial Issue - Part Seven of Eight
8c Slate Parliamentary Library
On this stamp, the vast majority of inks are non-transformative, in that the colour under UV light is either deep slate, or deep greyish slate, as it is under normal light. However, a few of the printings are made with transformative ink, which appears either greenish slate or black under UV, when in normal light, these stamps just appear slate.
Let's start with six stamps printed in non-transformative ink:
It is a little difficult to see in the picture, but the UV light brought out the greenish tone that was present in the ink of the first two stamps, making them appear much more greenish than under normal light, so I have classified them as transformative. The stamp on the right appears to be printed in black ink under UV, in common with many stamps printed on high fluorescent, or hibrite paper.
So there doesn't really seem to be a pattern, as far as which stamps are printed with transformative ink and which are not: the sheet stamps, booklet stamps and coils have all been printed with both types.
8c Violet Brown - Alaska Highway
The vast majority of inks used for this stamp are non-transformative inks that appear to be more or less the same shade of deep maroon, deep violet brown or deep rose lilac, that they appear to be under normal lighting conditions.
Let's start with four stamps printed using non-transformative ink:
The only transformative ink I have seen on this value occurs on the printing made on hibrite paper:
10c Olive Green - Jack Pine
This is one of the more interesting stamps in the series, in the sense that the vast majority of inks used are transformative. Most of the stamps in normal light are either shades of deep yellow olive, deep olive or deep yellow green. On the non-transformative inks, the shades appear much deeper under UV, but retain their overall character. On the transformative inks, the deep olives and deep yellow olives lose the olive and become either deep blackish green or black.
Here are three stamps printed with non-transformative ink:
The first two stamps are deep yellow olive and are printed on dull fluorescent paper, and have types 1 and 3 dex gum. The stamp on the right, is the same, but Winnipeg tagged with type 1 dex gum.
Here are the same three stamps under UV light:
The non-transformative ink only seems to occur on the printings made with dex gum.
Here are five stamps printed in transformative ink:
15c Deep Rose Lilac - Bylot Island
To the best of my knowledge, all of the printings of this stamp, except those on hibrite paper are printed with non-transformative inks. In normal light, the shades range from deep blackish purples and blackish lilacs, to plums to deep reddish lilacs. Under UV, these inks appear darker, but not significantly different.
Let's take a look at seven stamps printed with non-transformative ink: