Please ID Washington On Post Card

I gauge it at perf. 11X10.5.The postmark appears to have a date of 1919, but very hard to read. Am I correct in assuming I can eliminate no's. 538 & 536? My Scott's catalogue is on its way! Thanks for any help.

Looks like an offset, #525 to me.

Thanks,Kcaramat!
I was checking that as well. From what I understand, 525 is perf 11 all around. This really looks like 10 1/2 vertically.

The date looks like 1919 JUL 6.

This is Scott 525, the offset stamp, perf 11. Note comparison of the side of your stamp with the bottom:

Hastily done, with apologies, but it's the same gauge side and bottom.

It's not 536 which is perf 12 1/2 and should clearly look different regarding the perfs. It's not 538 which is an engraved stamp.

Thanks, guys. Checked again(kind of tough because it's attached to card). Definitely 11 all around. Thanks for the date, Hy-Brasil!

If I read correctly between the lines, you likely have a perforation gauge which is opaque, i.e., paper or metal. Two thoughts come to mind, which might help:

1. Find a clear plastic gauge.

2. Along the lines of what hy-brasil posted, use another stamp of known gauge as a gauge.

(I agree, offset, Scott 525)

Definitely looks like the offset printed #525. The color, alone, is the clue. The offset colors look a little 'chalkier' than the other issues of the same era. This is a paler green than the others - it is almost unmistakable. Color variations being what they are between batches of stamps, though, I suppose anything is possible. I have never seen a flat-plate press or rotary press 1c Washington with this color, though.

I think 525 also

Thanks Gents,
I'm constantly learning here, and am most grateful for you sharing your knowledge.

Another way to confirm offset is to get some thin foil and lay it over the stamp and then gently rub it with you finger. If engraved, it will show the engraving on the foil. If no transfer of details appear then it confirms that it is offset 525.

Thanks, 3193! I'll try that.

Quoted for truth.
Don

What Don said.

After seeing a few examples of the offsets of that era, you start to pick up this particular distinction in the printing process. The human eye is a truly exquisite instrument when married to experience. But in this case, it comes quickly, you will will see.