Printing Inks Used On The 1967-1973 Centennial Issue - Part Seven of Eight

Today's post is the second last of the posts dealing with the inks used to print the stamps of the 1967-1973 Centennial Issue. Specifically, I will look at the 8c Parliamentary Library, 8c Alaska Highway, 10c Jack Pine and 15c Bylot Island stamps.

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.

Non-Transformative Inks

Let's start with six stamps printed in non-transformative ink:

Here we have starting from the top left, a coil stamp in the deep greenish slate shade on low fluorescent paper, then a Winnipeg tagged PVA gum stamp on low fluorescent paper, and an untagged PVA gum stamp on low fluorescent paper. Both of these are deep slate.  On the bottom we have two deep slate stamps with dex gum, the middle one being General Ottawa tagged with the migratory OP-4 tagging, and finally a greyish slate stamp with PVA gum on medium fluorescent paper. 

Here they are under UV light:

Under the light, the stamps do appear to be slightly different because of the differences in paper, but the ink colours still appear to be largely the same as they do in normal light. 

Transformative Inks

Here we have a general Ottawa tagged coil stamp in the deep greenish slate shade on low fluorescent paper, followed by a Winnipeg tagged stamp with PVA gum on low fluorescent paper in the deep greyish slate shade. Finally on the right, we have a booklet stamp with PVA gum, printed in deep slate on high fluorescent paper. 

Here they are under UV:

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.

Non-Transformative Inks

Let's start with four stamps printed using non-transformative ink:

The three stamps in the top row are in slightly different shades with the left stamp being a deep purple brown, and the other two containing more maroon than brown. All are on different versions of dull fluorescent paper, and of course all have type 1 dex gum. The stamp on the bottom row is the deep rose lilac printed on a very white paper that gives a dead reaction under UV. It has type 4 dex gum. 

Under, UV light, the shades darken, but do not change significantly:

Transformative Ink

The only transformative ink I have seen on this value occurs on the printing made on hibrite paper:

The shade of this stamp is a deep maroon, on horizontal wove, hibrite paper with vertical ribbing, and type 4 dex gum. Under UV, the ink appears black:

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.

Non-Transformative Inks

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:

In this picture, the shades are very dark and appear almost black, which contradicts my classification of the ink. In actual reality, there is enough olive left in the colour that I have considered these to be merely very deep versions of the same colour in normal light, and therefore, I have classified them as non-transformative.

The non-transformative ink only seems to occur on the printings made with dex gum.

Transformative Inks

Here are five stamps printed in transformative ink:

These five stamps are all printed in deep yellow green ink. The stamps on the top left and lower right are both printed on a different type of low fluorescent paper with PVA gum: one is vertical wove, and the other is horizontal wove. The middle stamp is on the hibrite paper with streaky PVA gum (also known as spotty white gum). The bottom left stamp is on low fluorescent vertically wove paper with PVA gum and general Ottawa OP-2 tagging, with PVA gum. 

Here are these same stamps under UV light:

As you can see, the colour of the ink appears to be either very deep blackish green, as in the lower left stamp, or black (all the others). All of the stamps printed with PVA gum or the streaky PVA gum, that I have examined so far, are printed with transformative inks. 

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.

Non-Transformative Inks

Let's take a look at seven stamps printed with non-transformative ink:

On the top row we have three dex gum stamps, all printed in shades of blackish lilac or blackish purple. The first two are slightly different versions of dull fluorescent, horizontal wove paper, with type 1 dex gum. The stamp at the top right is the same, except that it is Winnipeg tagged. 

On the second row are two general Ottawa OP-2 tagged stamps. The left stamp is a reddish lilac, on vertical wove, low fluorescent paper with matte PVA gum. The stamp on the right is on similar paper, but has eggshell PVA gum and is a deep plum colour. 

Then on the bottom row we have two deep plum stamps. The one on the left is Winnipeg tagged, on vertical wove,  off white low fluorescent paper, with matte PVA gum. The stamp at the bottom right is printed on whiter, low fluorescent paper, with matte PVA gum as well, but no tagging. 

Here are those same stamps seen under UV:

The colours are clearly deeper, but the plums and balckish purples still appear to be blackish purple, while the reddish lilac stamp is still somewhat reddish, but much deeper. Hence my classification of these inks as non-transformative. 

Transformative Ink

Like the 8c Alaska Highway, the only printing of this stamp that is in transformative ink, as far as I know is the one made on hibrite paper. As with most of the hibrite stamps, the ink appears black.

The colour in normal light is deep rose lilac. It lacks the brownish undertone of plum, and is not overly blackish. It is printed on hibrite vertical wove paper with light vertical ribbing and type 3 dex gum. 

Here is the same stamp under UV:

As you can see, the ink appears black. 

This takes me to the end of my discussion of the inks on these four stamps. Next week I will complete my discussion of the inks on this series with the 20c, 25c, 50c and $1.