Research

Here is the Siegel census on sold 537a. There is wide variability in color! Yet all have certs saying deep red violet!?

https://siegelauctions.com/display_census.php?catno=537a

What I'm hoping to do is use standardized instruments that can collect wavelengths from the ultraviolet through the visible into the near infrared. Each collection will involve hundreds of wavelengths. The absorption of the light of any particular ink/pigment/dye on a stamp varies as I move through short to medium and long wavelengths. The resulting pattern will look somewhat like a bunch of uneven camel humps, with each pattern of uneven camel humps being representative of any particular ink/pigment/dye as a distinct molecule. It is like a color graph fingerprint. The idea would be that I can find unique fingerprint(s) for any different color shade(s), and get enough of a sampling size of each roughly equivalent group of color shades that I can do statistical analysis that will allow me take any test stamp, and categorize it quantitatively based on how it behaves in a spectrophotometer versus known samples. For example, #537 it will have a bigger Blue hump than light reddish violet #537b, but a smaller red hump than light reddish violet.

This becomes important when you consider that a lot of colors are actually combinations of separate fundamental colors. So when a stamp fundamentally has only one unique pigment (unique molecule) that naturally appears Orange it looks much different in the instrument from a stamp that looks the same color of orange to the human eye or photo camera, but could have been made by combining red and green pigments, so that when it is all mixed up it looks the same orange. Obviously the two stamps are different: one has a fundamental single orange pigment and the other has fundamentally green and red pigments that have been mixed chemically together to look like the same orange to the human eye.

Another type of experiment that can be done non-destructively is to see what metal ions might be in any given paper or the pigment that's used for the stamp printing: genuine pigments versus forged inks; genuine papers versus forgery paper. Among genuine stamps color shades may have different Metal ion characteristics - again a fingerprint of sorts - used for fraud detection and/or color ID. This I suspect is not as strong a test as the UV Visible test in the previous paragraph (for metal ions you need X-rays), so I'm not sure about this for differentiating between the different color shades as a way to compliment the data from the experiment I described in the previous paragraph (but I’ll give it a try).

Without going into a lot of other technical details just suffice it to say that there are several other techniques that can be applied scientifically to the stamp’s paper and ink to try and really figure out what color it is, what paper it is and whether it's genuine or forged.

For now to keep it as simple as possible, I will only study unused stamps, both with and without gum (gum can be analyzed the same as ink/paper).

The National Postal Museum has a variety of instruments that will help me in this task, but until the US Government Federal shutdown ends, I won’t have access to their Forensic Laboratory and support staff. Once I am convinced that the instruments are actually going to be useful in my endeavors, it's possible that I could buy my own instruments and set them up in a laboratory in my hometown.

A few years ago I actually called Amos Publishing and told him I thought they had an obligation to provide visual color definitions as color blocks of all the color variations in the minor catalog numbers that they described. Otherwise, how can I be expected to know what deep red violet looks like. The response was something to the effect of they are in the business of pricing the stamps and are not experts on identifying them. They rely on customers to have expertise, or to be able to hire the expertise, to know which examples they have go with which color.