Canada Booklet Pane Perforation Difference Not In Stamp Catalogues

The booklet pane above has 11 1/4 x 11 perforations
and the booklet pane below has 11 x 11 perforations.
This perf difference is not noted in Scott and Unitrade.

Good catch jogil
I have found significant differences on stamp perforations, but lots of people just don't care, there tell me to just round off to the closet number..It is a shame.

Robert

wert: 1/4 perforation difference is something to note for this.

Tell me about it..Take for instance NFLD stamps that are classified as a certain perf in a catalogue and when I go to my detailed NFLD catalogue there are some that have 10 different stamps..To me that means 10 stamps are added to my collection.

jogil..Start up a new post for lets say "new perforations found" and see how many people will post.

Robert

Jogil, I suppose they are actually 11.25 x 10.94?

BeeSee: Yes they are.

This is one of the distinguishing differences between 164a/164as and 164ai/164ais booklet panes and booklet stamps.

The difference in perforations is 11.25 minus 10.94, which is 0.31.

Say the stamps were perf 11.2 and 11.4 respectively, for a difference of 0.20, they probably would have been listed, even though the difference is less than Jogil's stamps.

That is because Scott rounds up or down to the nearest half to determine the listed perforation. In the first example Scott would round the 11.25 down to 11 and the 10.94 up to 11 and call the stamps equal. In the second example they would round 11.2 down to 11 and 11.4 up to 11.5 for a difference of 0.50. This would meet their listing criteria - which to me is flawed.

BeeSee: What is interesting is that Unitrade does not follow Scott's perforation listing for many issues but for other issues it does. What is important is that if more specific perforations are useful in distinguishing certain different printings then they should be used such as 1/4 in this case. Unitrade has a chart listing different Kiusalas perforations for the Small Queen stamps.

The way I look at this is that there are 40 perforation holes across the centre of the upper pane and only 39 across the centre of the lower pane. This shows clearly that a different perforating head was used for the two panes and that they are very interesting from a stamp production point of view. This gives rise to obvious qustions such as

When did this change take palce and why was the change made. Or were 2 different perforators used throughout the life of these stamps ??

AQ

All BABN Arch and Medallion booklet stamps were flat plate press printed except for Scott/Unitrade 164ai/164ais. It appears that originally it was planned to print all booklet panes by Stickney rotary press printing (164ai/164ais), but the printer experienced printing plate damage and perforator adjustment problems so that it was changed to flat plate printing. The perforator that perforated web-fed Stickney rotary press stamps was an all in one web-fed (horizontal) bar and (vertical) wheel perforator (11 1/4 x 11) and the perforators that perforated sheet-fed flat plate press stamps were two sheet-fed rotary wheel perforators (11 x 11) with one perforator for the horizontal perforations (11) and another perforator for the vertical perforations (11).

Jogil, we also know Kiusalas does not work very well for the small queens.

BeeSee, true especially for the missing perf 12 gauge. What is your solution?

My solution is a Canadian Specialized Perforation Gauge. This gauge is based on actual known perforation pin/hole distances, based on the number of pins/holes on the known wheel diameters - much information comes from your research Jogil

Here is an image showing the obvious difference between perf 10.94 and 11.25 over 2 cm and 20 holes.



It was drawn 100% to scale but enlarged for this illustration.