I learned a new term today. I looked at the listings that jimjung just advertised in another thread, including a "365i Identical Pair Variety". I looked at it and said, yeah, those look identical, what's so special about that?
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Many of you probably already know, this stamp normally comes from a se-tenant block of 4 where adjacent stamps are a different design, but because of the layout of the sheet, there are occasional "identical pairs" of two adjacent stamps sharing the same design. Interesting. I never knew about this. Here is a full sheet (from a different eBay listing).
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It is a listed variety. Since this was Canada's first se-tenant design, I wonder if this was intentional or a design mistake. If intentional, why just the fishing and skiing have Identical Pairs, not the hunting or swimming?
It appears that blocks taken from the left and right edges of the sheet will always contain one of each of the four designs, but blocks of four taken from the middle of the sheet (including the middle column) will contain only 3 designs (with one of the designs duplicated, either as an identical pair, or diagonally across from each other). The middle column also provides for a se-tenant strip of four, while the other four columns only contain alternating pairs of two designs. Interesting layout.