Mm Size For Coil Waste Issues

Actually, I have 8 stamps (suspicious Scott 552s and 610s) with the confusying measurements... I really need your suggestion - does it worth to send these for certification? I am asking especially about the Scott 552, which supposed to be 18.5-19mm x 22mm, but I have at least four that are ~19.50mm x 22.40mm
What would you do if you were me?
I have more scans, if someone is interested to review.
Please kindly advise! Please...

Aurora, the answers to your questions have been given in this lengthy post. Chances that you have a rare stamp in your collection are extremely slim, but keep reading about these. http://stampsmarter.com is THE way to go. And if you after a long time of research you still feel you have a winner send it off!


Peter

Thank you, Peter.
I use StampSmarter.com a lot; this link is the best: http://www.stampsmarter.com/1847usa...ntifier.html
Actually, I can send all of the stamps for certification saying that I need certificates that these are Scott 552s, and we will see what will happen next )))
Thank you all.

How do you accurately measure to the 0.1mm let alone 0.01. I would expect some microscope or a magnifier with a calibrated scale.

If you say a dimension is 21.40 do you really think you are accurate to .01 to determine if is 21.34, 21.35, 21.36?

Hello, I also think that these measurements by Aurora can't be that precise. With a good "home" measurement you can perhaps see differences of 0.1mm but not less.

But I understand Aurora very well, and the mm sizes was also the reason for this long living thread here. I think there is a really big need for beginners to learn about this.

What Aurora and me and also others (like the one I linked some posts ago) just don't understand and nobody has answered until now is just the simple question:

What should we think about a perf 11 stamp that has many signs for flat (ink setoff, design color, printing quality), but has a obviously larger size than flat? (19,00 or 19,25 x 22,25 or 22,5)

Did the experts here also see such stamps already, and what did they do with them - certification or flat staple?

I use an Electronic Digital Caliper (new), high quality scanner & Paint software for comparison. And - yes, I do have a few professional magnifiers and a microscope. )))) I love this hobby!
Thank you very much for all the suggestions and links. This Forum is great.

Joker, very good question about setoffs. Anyway, will you show your stamps?

Again, exact measurements are ineffective. Instead, compare stamp height and width starting with a stamp with a known identity. Then, keep in mind that flat plate paper shrinkage across the grain is not exact. Some stamps shrink more than others after printing depending on how wet the paper was at the time of printing.

I have not seen any mention of flat plate booklet pane stamps. They were printed on "special paper" with horizontal grain. The resulting stamps are slightly wider and shorter than sheet stamps. Many collectors and some eBay sellers have confused booklet pane stamps with coil waste printings. A useful exercise would be to collect a group of the common 11 cent Hayes stamp of the Fourth Bureau issue flat plate and rotary press printings. If the stamps are carefully separated by size, three populations will result. The rotary press stamps will be taller than any of the flat plate stamps and will have a sharper appearing design. Some flat plate stamps will be slightly wider and shorter than others. Why should this this occur?

After booklet pane production was converted to rotary press in the late 1920s the leftover paper was used to print some higher denomination flat plate Fourth Bureau issue, some C11 Beacon airmail, some E13 Special Delivery and all of the Special Handling 1928 printing stamps. Search for "Special Paper" on the United States Society web site.

I hope it is abundantly clear, that attempting to measure stamps in isolation will be ineffective and that not taking booklet pane stamps or special paper into account will produce fatally flawed results and confusion. As a footnote, not all tall rotary stamps are exactly the same height. Vertical rotary coils were printed on presses with smaller cylinders than rotary press sheet stamps and are very slightly taller as a result. Despite that, it took decades to debunk the notion that 1 cent Franklin Fourth Bureau Scott 596 was not "coil waste". They were perforated from a few left over part rolls of sheet stamps that had accumulated during production of the perf 10 Scott 581. Finally, Scott changed the designation to "sheet waste" after it became abundantly clear that the 2 cent Harding rotary perf 11 sheet waste stamp could not have originated as coil waste.

Again, attempting to measure stamps will be ineffective, especially if any printing scenarios are overlooked.

Wow.

Another way to understand the difference between flat plate and rotary press printings is to keep in mind that the size of the original die was for definitive stamps was nominally 3/4 by 7/8 of an inch. Bending the plate to fit on the rotary press cylinder stretched the design enough so that the height or width of the printed design will exceed one of the original dimensions depending on the direction of bending. Any stamp not exceeding the height or width of the original die must be from a flat plate printing.

hello cfrphoto and thank you very much as always.

I understood it and have two questions more :).
1 - you mention that the rotary design is more sharp, probably because the lines are finer? For me, the design of some rotary has fine lines but does not look sharper (or "better") than flat, but flat looks like "better printed". So did you mean with "sharp" the finer lines, not the personal impression?
2 - the flat plate booklet pane stamps (thanks for mentioning that!) are slightly wider or taller, so not both?

by the way (and also to Aurora): I don't have a huge flat stamp here which I could show, I had one but it's not really huge after all... but I am always like that that I want to check all possibilities before I start running (should change this, would make life easier).

You are correct, the lines are finer on rotary press printings. To my eye, the lines on many flat plate printings of the period appear to be a bit blurred in comparison. Try comparing wet and dry printed Special Handling stamps all printed from the same plates. The wet printings exist on normal and special paper. The dry printed stamps are larger because the paper was dry when the stamps were printed.

Booklet pane stamps shrink in the opposite direction from sheet stamps. Please reread the post above about die size in relation to the printed size of the stamp.

It is time to bring this discussion to a close.

OK thank you also again.
Of course we can find an end here (I didn't revive it but questions are always appearing...)