Canadian Philately - The Stamps and Postal History of Canada 1851 to Present by Brixton Chrome

Today, I turn to another aspect of this issue that has received little attention from philatelists: the perforations on this issue. Most collectors with a passing familiarity know that five basic perforations exist, but they tend to pay little attention to them, in large part because the stamps with different perforations are often very easily distinguished on the basis of other characteristics. However, as we shall see, there are other aspects to the perforating that should be understood by anyone opting to specialize in this issue, for it is the possession of this knowledge that opens up the possibility of important discoveries being made later. 
There are three attributes of perforations that are of interest here:


Whether the perforations are line perforations or comb perforations.What the measurement of the perforations are (i.e. the gauge), and whether there is any significant and consistent variation to be found.Whether the perforations extend all the way through the selvage of …

Today's post is the second post that will deal with the tagging used on the 1967-1973 Centennial Issue. Last week, I looked at the Winnipeg Tagging, which began to be replaced in late 1971 and was fully superseded in 1972, by what is known to collectors as General Tagging, or Ottawa Tagging. This is now the standard tagging that is found on nearly all Canadian stamps since that time. However, the process of replacing the Winnipeg tagging with the new Ottawa tagging, was not without its experimentation as well, and it is this experimentation that has led to the existence of additional collectible varieties that go beyond the mere Ottawa Tagging itself.

The points of interest, where varieties occur, that will be discussed in today's post are:


Variation in the chemical composition of the taggant compound: OP-2 versus OP-4 tagging.Variation in the colour of the tagging under UV light.Intensity of tagging bars in normal light.The width of the tagging bars.Tagging errors.Spacing of …

Today's post will be the first of two posts that will explore the tagging that is found on many stamps of this issue. Collectors with even a passing familiarity with this issue will know that there were two basic types of tagging used on this issue: Winnipeg tagging and Ottawa tagging. Today's post will look at the first of these in depth: Winnipeg tagging. The Winnipeg tagging was first introduced in 1962, and so was in use on all printings of the low values from 1967 until 1972 when Ottawa tagging began to replace it. Interestingly, the tagging was not introduced on the high values until December 9, 1969.

Tagging is of course, a chemical overprint that was applied to the surface of the stamps after printing. Like any overprint, there are several attributes which can show variation, and are worthy of study:


The chemical makeup of the taggant compound used, as evidenced by its reaction under UV light.How much taggant was applied, as evidenced by how visible the tagging is to t…