Showing posts from August, 2017

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

Today's post continues with where I left off last week: the shades of the low value centennial stamps as they appear in ordinary light. Last week I dealt with the 1c, 2c, 3c and 4c values. This week, I will look at the 5c through 7c values. 5c Blue - Fishing Village Of the four stamps I am examining today, this one exhibits the widest range of shades, ranging from deep violet blue, all the way to a deep bright blue. The range does not seem to be confined to either the dex gum or PVA gum stamps showing similar ranges of colour. However, I have not seen the deep indigo shade on the PVA gum stamps. The BABN booklet stamps do not show a range however, with all the booklet stamps I have come across being more or less the same shade. For this stamp, I find the best parts of the design to focus on in comparing shades is either the Queen's hair or the lower left corner. Dex Gum Stamps - All CBN Of all the stamps printed of this value, it is the sheet stamps with dex gum

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

Today's post will delve into another aspect of the Centennial issue, that I feel has received less attention than it should: the printing inks. Apart from the fluorescent orange ink variety of the 6c orange, scarcely any attention is given in Unitrade to the immense variations in ink that can be found on this issue. In discussing the inks used, it is necessary to distinguish between how the inks will appear in normal light, and how they appear under ultraviolet light. In Canadian philately, the long-wave ultraviolet light (UV) is used to study modern issues, as it is this end of the spectrum to which the inks and tagging react the most. This is the safer wavelength of ultraviolet light as well, and is commonly referred to by laypeople as "black light". It is possible that two inks that appear the same in normal light or long wave ultraviolet light, might appear different under short-wave ultraviolet light. However, due to the dangerous nature of this type of light and th

The Gum Types On The 1967-1973 Centennial Issue

Overview The topic of gum on the Centennial issue is one that has not received very much attention at all since collectors became aware of the basic difference between dextrine and PVA gums. However, like any chemical compound, the composition of the gum on this issue showed considerable variation as the post office experimented with different formulas as they transitioned away from dextrose gum towards synthetic PVA gum. Indeed the special hybrid gum, termed "spotty white gum" by collectors, that first appeared on a limited basis in 1971 was almost a cross between dextrose and PVA in the sense, that it had most of the properties of PVA gum, but it possessed much of the shine and thickness associated with dextrose gum. In addition to variations within the three major categories of gum, there was also a significant difference in the properties of the gum used by the British American Bank Note Company (BABN) on the stamps that it printed, and the gum used by the Canadian Ban