I got this item out of a bulk revenue lot from eBay
. I have several 1st issue plate number singles, but have not been able to acquire any actual plate blocks. This is a lower-left corner plate block of 24 of R6c. Not a rare stamp, but plate blocks of any of the stamps aren't exactly common.
It's been heavily reinforced all the way around the back. A bit of overkill, IMO, but it is what it is.
It was only as I was imaging it for the website that I examined it a bit closer. I believe this to be not R6c, but R6d. The only previously reported multiple of R6d according to the Curtis Census is a single pair.
This block showcases why we see so many 1st issue revenues that have all the characteristics of being silk paper; the paper color, texture, thickness, etc., that cannot be classified as silk papers due to the lack of blue threads. I have seen other silk paper multiples where only 1 or 2 stamps in the block have the blue threads, and this is another example of that scenario.
The plate number single at lower left contains 3 blue threads, two on the obverse of the stamp and one in the selvage on the reverse side of the stamp.
The only other blue thread I have been able to locate is on the reverse of the 2nd stamp from the right on the top row, across the block from the plate number single.
The paper color from the back looks darker than one would expect from a silk paper, but I believe that is due to the gum, which has darkened over time. The lighter obverse color is more in line with what one would expect.
Given the extensive reinforcement, creasing, and other faults, as well as the PF's puzzling stance of only classifying stamps within multiples that contain silk threads as actually being silk papers, the remainder being classified as regular paper (see the 2011 TAR article by Michael Aldrich concerning his R41d discovery block and the -- in my opinion incorrect -- verdict rendered by the PF), the block is likely worth nowehere near the Scott value of $6,600 (24 singles x $275), but I think it has some value as the largest reported multiple.
A nice find, if nothing else.