Mystery Rotary 2c Washington

Can you help me ident this fella?

I'm wondering if its a real rotary or an anomaly of printing.

Perf 11, no obvious wm.

Obviously not a 546 type III, and impossibly a 459 with added perfs.

Is this a true rotary? Micrometer reads 19.57mm edge-to-edge width against a square at 90 degrees.

I scanned it with a flat plat template for visual aid.

Is this just a standard deviation?

I feel like i'm missing something obvious.

The fact that the stamp has a straight edge with guide line on the right makes it either flat plate printing or offset lithography printing with perforation 11.

It's a #499e from a booklet pane. BPs are slightly wider that sheet printed stamps due to the manufacturing process being different from sheet stamps. I believe the paper grain was 90 degrees opposite for sheets when printing was done, which causes somewhat shorter, wider issues. The degree of the difference depends upon the shrinkage of the paper. Note you have a straight edge on the right indicating a BP.

Mystery Solved! Thanks to both of you.

The stamp is clearly an engraved type I flat plate stamp. Because it is slightly wider, it would be a booklet pane single. The guideline places it from a position B, H, K or N booklet immediately to the left of the guideline. (See the booklet pane section in the Scott US Specialized Catalog.) Normal sheet stamps printed on vertical grain paper which would shrink in the horizontal direction. Booklet pane stamps were printed on horizontal grain paper which would shrink in the vertical direction.

It would be helpful to maintain more clarity in these discussions. Before commenting on the printing method, try a visual comparison with known stamps first. Guessing will just mislead and create confusion.

Clark

Hello coilfan. Your stamp appears to be type I. The only type I that is 19.5+ mm is the #453 coil or the #459 imperforate. I think that your stamp is from a booklet. The paper grain orientation caused booklet stamps to be significantly wider than the sheet stamps. Try measuring the width again. Booklet stamps come close to 19.5mm in width and I've never found one to be 19.5 mm or more. I imagine using a micrometer to be difficult. I use calipers and even then it's nearly impossible for me to measure with them. I set my calipers to a certain width (19.5 or 22.5 mm) and then use them as a go-no-go tool.

It appears that I'm late to the party

Yes, sorry, I used the digital calipers, the cheapo from harbor freight, and I did zero it first. I'll chalk it up to chinese math.

I always examine the reverse first, usually flat plate printed stamps have ink offset from the stacking of sheets!