1923-1926 Washington #595 How To ID?

I noticed that the measurements for 595 are different for Scott and Micarelli 22.75mm and 22mm .

DOES ANYONE KNOW WHY.?

Thanks

yes there are many differences between Scott specialized and the Micarelli book, also many typos in the Micarelli, seems that they care more about the Scott specialized.

but about your question: in this case there is no difference... in both books of mine they say 19.75x22.25mm.

best guess on identification here?

There is no "why". Measurements in the Scott Catalog are to the nearest 1/2 millimeter, not nearly accurate enough to be used for stamp identification. Width and height comparison with a known stamp is the most reliable way to determine size and printing method.

Scott 595 resulted from perforating imperforate coil roll fragments vertically and horizontally in a flat plate perforator resulting in a perf 11-72 stamp. Scott 579 started with perforated, uncut coil fragments producing a perf 11-72 x 10-80 stamp.

Coil stamps were intended to be distributed in continuous rolls. Rotary press sheet stamps were perforated in both directions and cut into sheets with selvage on all sides. Top and bottom selvage on coil rolls was cut off. Coil waste sheets did not have side selvage. Experiments with the "electric eye" perforator in the 1930 produced sheet stamps with bars in the selvage needed to guide the perforator.

Horizontal gum breakers ridges will normally be found on rotary press sheet stamps with original gum. Also, later printings of 634 are a brighter carmine with less ink wash on unprinted areas of the design.

This information is on the Internet or the Scott catalog and other reference books.

while this is all very informative I have little stamp knowledge and I would greatly appreciate if someone can just tell me from looking at the washington 2 cent block of 6 images I posted exactly which variety they are? should I start a new thread or is it ok to ask this here? thank you all scf members your help has been a blessing!

634 experimental Electric Eye plate variety from 1935-1938.

634a...type II? odds are no its type I i keep telling my boyfriend but he swears he can tell the difference. without going through some process on stampsmarter or whatever can you tell---cfrphoto or anyone---if this block is type I or type II?

ok I looked up electric eye got it. thank you!