Scott 980 & 986 With Curious Ink Effect

Anyone know what would be the specific cause of this ink effect? I assume some kind of environmental effect. I have seen many stamps of this color in this series where the ink in either non-luminescent on the entire stamp or the entire stamp appears to have luminescent ink. I have been trying to identify inking varieties in many US issues and this one makes me wonder if others that are all luminescent ink are due to environmental effects or different ink.

Looks like they were in a stock book and the bottom half against the plastic is normal, and the top half against the backing paper of the page in front of it caused toning. Or vice versa. Definitely post-production damage.

Here are examples of 980 with either ink appearing non-luminescent and luminescent. As I mentioned you can find these stamps with this colored ink in both varieties. Colors vary a bit from the above examples because they were not take the same time as above and lighting conditions may be slightly different. I should have mentioned these are all taken under long wave UV light. In the ones below the paper doesn't appear toned in either one. Toning tends to make the paper appear brown under long wave UV (note some paper naturally appears brown under LW UV).

John, do you think the luminescent varieties or the other way around are just altered versions of the other? Or are they different ink types?

I do not have any direct experience with these particular stamps, but you show the same effect on two different stamps issued 10 months apart. A post-production storage/handling issue is a far simpler explanation than something happening on the press with the inks. Nor do I have them in front of me.

Given that the Post Office did not start experimenting with luminescent stamps until 1963 you can rule out anything production related here. That leaves storage, environment, contamination or any combination thereof.

Red stamps are always troublesome on color changes

The statement "Post Office did not start experimenting with luminescent stamps until 1963, you can rule out anything production related here." is true only from the context of fluorescent paper and phosphor tagging. Boerger who wrote the "Handbook on U.S. Luminescent Stamps" used the term generically as luminescence encompasses both phosphorescence (tagging) and fluorescence (bright papers).
Luminescent or more specifically fluorescent ink can be found on many early US issues as well as modern. Note phosphorescent ink has been used on some US and World Wide stamps as well. What I found curious is what would cause a non-fluorescent ink to become fluorescent or vice versa. Almost all of the early stamps with red violet ink as defined by Scott can be found in both varieties as I have shown above. I know of well over 200 US stamps that have fluorescent/luminescent and non fluor./lum. versions.

What pre-1963 U.S. inks do under UV light with regard to later tagging is a coincidence and to a certain degree, Monday morning quarterbacking.
Rather than speculate and guess, I would recommend a research trip to delve into the BEP archives. Ink formulations, how many times did each set of plates go to press, etc?

It appears that what you show are two different situations
The first being a pair of stamps which more than likely show storage damage.
The second pair are more likely to be from separate printings.

Again, I have not studied these in any depth and do not have your examples to examine. To be more transparent to us, it would be helpful to have normal and UV images of each groups presented done under the same conditions.

I am not trying to Monday morning anything. I was pointing out what I thought was a misleading comment.

You are speculating that the two sets of images are two different situations. If the first image is due to environment conditions, which I expect they are, then it is possible the second set is also from environmental conditions.

I also don't appreciate the transparency response as I am not trying to hide anything. I see to many responses such as these so I am done with this forum.

I was not trying to be insulting, but to get across the point that more complete information gets better and more accurate responses from the Forum and that we like to see pictures. Specifically, similar images in visible and UV illumination. Nothing more, nothing less.

But have to fear, I have added you to my very short list of participats here to which I will never reply to or help again. I have better uses of my time.

mstocky2,
Let's get back to stamps stuck in a stock page "pocket" where part of the stamp is in broad daylight (or office light, fluorescent light bulbs in use, etc.) and part of stamp is covered from external light by the pocket.
What happens over time? Recall reports over couple decades of stamps on display under glass in post offices? ("blue" inks turn green, yellow inks disappear, and so on).
Have you ever seen a list of ingredients in a can of paint? Simply imagine one of the components of ink in the BEP's formulation is luminescent. Simply imagine that light exposure over time fades that component (whether our eyes "see" that component or not). I think you see what might be observed, when a UV light is shown on given stamps after such exposure.

(You have to allow for brief lapses into pedantic responses from time to time. In this case, given the basic factors I brought up, talk of having to gain a semester's education in BEP ink formulations to understand this particular phenomenon did appear as overkill. It is more apropro for those wanting to delve into, for example, the "range of reds" in colors of late 19th- early 20th-century stamps and so on.)

John. I want to sincerely and publicly apologize for my comment. I have nothing against you and actually respect you as you are one of the few who are always willing to answer peoples questions. It was pretty harsh and totally out of character for me and I am still wrestling with the question of why I did it. I understand if you don't respond in the future. Again my sincerest apology.

Apologies to all, let me try to get this topic back on track.

John's requests are good ones so here are the front and gum side of the two stamps under normal light plus a few more samples. I expect John's suggestion that the luminescent portion of the two stamps initially posted where against the plastic portion of a stock page is most likely correct. Certain plastics can have the plasticizer in them migrate into another material they are in contact with. This may responsible for the luminescent effect.

These images take some time to capture good results under LW UV hence the delay in posting. Most images you see taken under LW UV have a very blue tint to them. The images I show are fairly close to what I observe when viewing the stamps under LW. As always images will vary on different monitors but they should be in the ballpark.


For the two initial samples posted, there is no visible difference when viewed from the front under normal light. Inked image is somewhat visible from gum side.

I also took an image under 40x optical microscope using LW UV of the transition area.

You can see form of bleed out in the luminescent portion of the samples. I expect this bleed out is a reaction to some form of environmental reaction/impact and contact with stock page.

Below are some additional examples where the entire image is either non-luminescent or luminescent. These may very well be printed with different ink formulations as examples of either type are fairly easy to find. There are many more examples that can be found of other early US stamps


Below is a slightly different color.

All images where taken side by side under same LW UV lighting. Visible differences, for example 866, in the background come from different paper many of these were printed on. Different paper brightness can also effect the color ones sees. These views come from a slide presentation I have created to document the many US luminescent and non-luminescent ink varieties.