Scott 554...perforation Difference..??

Hi guys

I just started going through my American stamps..Going to be a big job, got hundreds from 1970's back to later 1800's

This (I think) is a Scott 554, but why are the perfs so off..Could it just be from moisture, etc...?

Sorry about the quality, from phone to enhancer program.

Thanks Robert

#554 flat plate issues were perforated 11, #583 rotary press issues were perforated 10, #579 11x10, #634/634A 11x10.5, #595 11

http://www.shaulisstamps.com/tips/2...thBureau.htm

Hi Robert,
The right stamp is perf 11 x 10.5, the left one is 11 x 11 (issued several years apart). Paper does have a grain, but I am unsure if that explains the difference you are seeing. Perhaps Clark will weight in...

Additional ID info http://www.stampsmarter.com/1847usa...ntifier.html
Don

Don,

The stamp on the right is a 634 and the one on the left is a 554. Flat plate stamps were perforated 11-72 (the second number is the spacing between perforations measured to the nearest thousands of an inch (0.001"). Rotary press sheet stamps were perf 11-70 x 10½-75. Although the top and bottom of rotary press stamp are also labeled as "perf 11", perforation spacing differs by 0.002". Over 10 perforations, the difference is 0.020", enough to be visible when the perforations are compared.

Paper shrinkage has no relevance for perforation spacing. Although paper may shrink across the mesh (grain) after printing, perforations are not applied until after sheets are gummed and dried.

Also, it was unfortunate that the OP failed to show a complete image of both stamps. Horizontal perforations on vertical rotary press sheet stamps must be aligned between rows. Articles by Lou Repeta in the United States Stamp Society "Stamp Specialist" describe rotary press sheet perforators in detail. Also, the OP should have oriented the image with the stamps in the vertical direction as they would normally be viewed.

Also, I may not post if stamp images lack detail or may potentially detract from the discussion. I made an exception in this case because Don requested input.

cfrphoto..99.9% of my posted images are produced with my scanner..Ued my cell because it is so hard to line up perfs on a scanner, and they usually shift..Forgive me.

Robert