Al Shaw t206 blue uniform variation...

[steve B]

Originally Posted by sreader3

Hi Pat, I would love to see a thorough and incontrovertible explanation for the differences in color with regard to Shaw (St. Louis), Stovall (Portrait), Turner, etc. I am certainly not qualified to provide one. Perhaps Steve is (hi Steve) but I have yet to see an explanation for these differences that is comprehensive or at least one that laypeople can understand. Merry Christmas everyone!

[If someone wants to write an article explaining these color disparities I will be more than happy to post it on my website! ]

It can get a little complicated, because the colors can vary for a few different reasons.

The inks were hand mixed, a situation that persisted for some colors into the early 1980's and maybe beyond. A particular blue would start with a Cyan base and a bit of various other colors would be added to get the "right" shade of blue. By the early 80's that was mostly for solid color areas with a special color like a company logo. It made the then color separations much easier and less expensive.
Different pressmen would mix the same color a bit differently, even if the recipie called for exact weights. Basically nobody took the time to measure the smaller weights. If it was 1ounce Cyan, half ounce white and a few grams of Yellow, the yellow translated to a "drop" which could be dime size, or quarter size. And had a noticeable effect on the actual color.

Registration issues can change the perceived color, although that's unusual on T206s.
Todays cards are almost entirely computer generated halftones, and colors can vary with registration. I had one set where I had kept doubles of not only a blue banner, but a purplish banner and a greenish blue banner.
Under the 40X magnifier, they were identical except for the registration. The purple ones had red slightly off making the blue appear reddish enough to seem purple. The greenish blue had yellow slightly out of register.
saved a bunch of space by moving most of them to the extras box...

This stuff happens for Stamps too, and some of the articles are very technical. There's a group now that's doing x-ray diffraction to figure the composition of the inks so they can tell colors apart more reliably. Biggest revelation to date is that a reddish brown ink that was always assumed to be rust in a semi-hardening medium like linseed oil was found to contain no Iron whatsoever!