Scott 248 - What Is The Reason For This Mark..?

My Scott 248 pane has a mark in the top right corner.
Unitrade classifies the pane as...

Upper right pane.
Red plate # 1
Black plate # 4

1 - Is is clarifying it as pane 4...?
2 - Proof readers mark...?
3 - Standard mark...?

Robert

Probably your guess is correct - black plate # 4

Peter

That's what I was thinking Peter...Don't remember seeing this oddity on other panes..But it could be a standard thing.

Robert

That's my understanding as well - it identifies the plate number of each colour. A quick ebay search for any of the Royal Visit series plate blocks will bring up dozens of examples and combinations. I also noticed this on a plate block for a more recent stamp (Scott #439) and I assume it's the same thing.

This is very pronounced with other countries such as New Zealand where the inscription blocks show the plate numbers for each colour of ink. E.g. 1 1 2 2 1. In some cases it could read 1A 1B 2A 2A 1A thought I admit to not knowing the purpose of the letters. Perhaps 1B for example would refer to a Plate 1 which has been repaired or corrected in some way. Note to self: ask this question on the world forum.

Could very well be itma...Now the questions to ask is this...

1-The company that is hired to print stamps for Canada Post is probably not worried about which pane is witch on a sheet of stamps.

2-Canada Post is more in line with receiving these stamps to sell to the public to make money, and to them a pane number is probably not in their thought process.

3-There are 3 people associated with stamps, the printer, Canada Post and the stamp collector...The stamp collector is the only one interested in plate and pane identification.

4-Stll leaves me with why they do it..?

Robert

The printer is very interested in the plate #.
That is how they can trace damage and wear - and perhaps correct it or retire a plate. The printer will also track how many impressions come from each plate to determine which plate alloy works best for longevity and bidding prices for printing contracts, etc.

Canada Post is probably least interested in the plate number used by a contractor. They merely want a printing contract filled for X-million stamps.

The collector's chase of plate numbers is contrived marketing to a considerable extent, IMO.

Now that makes sense John...When I was in the printing world when I was younger, we just re burned a new plate.

So basically my "-4" indicates a possible problem...Nice.

Robert

"-4" merely indicates it was printed from the 4th black plate. I would not assume anything more than that.

Unitrade notes 5 red plates and 4 black plates with all number combinations existing (except 5-1). While I have no direct knowledge of the printing floor operations, it appears plates were traded-out regularly and fairly randomly, I would guess for a thorough cleaning. Take off the dirty plate, replace it with any one of the clean plates and keep the press running as constantly as possible.

Given that there were 5 different plates used to print the frame (red) and 4 different plates to print the portrait (black), there would have always been the possibility of having an inverted error when two separate plates were used to print in two different colours such as for the Seaway inverted stamps.