Help With This 518 Frank

1st thing I noticed were the dimensions.
I don't have one that I particularly want to chop the corners off for now, but I have a ton of perf 11 Franklins to compare it with side by side, all of which measure at 18.5 x 22, except this one measuring at 19.1 x 21.5 .







I know that a rotary press should be longer on either dimension, so it can't be that.

But I read somewhere that according to the paper used, design elements may shrink (amongst other inconsistencies depending on the paper type).

So I compared the backs and found that rather than having a typical flat solid surface, it has a mesh weave similar to those of the American "Banknote" series.



I don't know what those numbers mean written on the back.. but does anybody have any ideas?
Let me know if you want any more pictures.

Also, doesn't look like anything mentioned here:

https://www.stampcommunity.org/topi...PIC_ID=45366

but more like what I referenced above.

Thank you

Here's a closer image of the reverse with a #511 (which basically resembles all the others)

These are all going to be flat plate printings. Your $1 stamp is both shorter and wider than the other stamps of the series. This is exactly the same characteristic of booklet stamps of that era where the dampened paper was turned 90 degrees for printing resulting in booklet stamps also with images both shorter and wider than their corresponding sheet stamp. When the paper dries is shrinks differently with the grain vs cross-grain. This change in paper orientation would explain your stamp.

Here is a strip of 518 and a booklet pair of 374, provable by the straight edges.


And overlapping to show the same height/width ratios:



I don't know if the entire print run was done this way, but your stamp and mine show the same thing, but .....

Add: Durland's plate number catalog notes only top and bottom plate numbers, yet top, bottom, left and right for the lower denominations, which drove me to Johl's volume 1 of "US postage Stamps of the Twentieth Century", which notes a plate of 200 instead of 400 and a correspondingly smaller paper size to print on.

John Becker Thank you as always for the very informative comments. That makes a lot of sense! The reverse looks 'shriveled' probably from the drying process.

I noticed that StampSmarter and other resources claim that the size of every flat plate printing of this series should be 18.5-19 x 22.
They give leeway to the horizontal by 0.5mm (possibly for the reason you mentioned above), but not to the vertical...

If the shrinkage of my stamp is indeed due to the drying process of booklet stamps, shouldn't the flat plate size reference for this series in catalogues be 18.5 - 19 x 21.5 - 22 ?

Yes, the dimensions for 518 should be different in the literature.
Scott is virtually silent on the orientation of paper for printing booklet stamps.
Also, far better to use stamps of known printing methods and dimensions and not use a ruler.
There is little/no reason to measure most stamps.



Your stamp has been soaked/dried from its mail piece by a collector. No trace of original manufacturing would remain. (It could use another soaking to clean up the hinge remnants, imo.)



rather ... the different height/width ratios in the finished stamp is due to the 90 rotation of the paper grain similar to that in most booklet stamps of that era. The drying process has no connection.

Ooh I see. Because 518 wasn't put into booklets but rather from sheets all with the same plate #, and their process with the 90 degree rotation was an exception to how the other flat plate denominations were made.

So basically, all other 518s should be the same size as mine..

Yes, it's very strange how this isn't listed anywhere and is just clumped in with everything else.
Seems like an important distinction!