How Does A Scott #1033A Silkote Paper Look Under UV Light?

Hello,

I have seen many stamps that could be 1033A, but never was sure.
I don't really bother with certification in most of my stamps.

So perhaps I could learn here if there is a hint for the 1033A under UV light?
What would it look like?

Interesting question. @slhoffman stated




https://goscf.com/t/56286

Hopefully someone will respond, but, if not, look at your current samples and see if some other sample looks different. I could post an image of that, but you probably have a 1033

Hope someone posts one.

Then I suggest you not bother with 1033a.





The above from a very large dealer which is selling silkotes with PF certificates.

Lastly Siegel Power Search has 25 returns of which 23 have one or more certificates. Two, a single and a block of 4 without certificates sold at give-away prices if they actually sold.

The best method is to have a genuine example for comparison. The paper is brighter and the shade a bit lighter; the impression is a bit sharper. But all of these differences are slight enough that a comparison is really required.

thank you all. I don't have a candidate here, but I am interested in paper and paper fibers as well as paper coating, so I was asking this question.

Has anybody ever seen a 1033a under UV light, and if yes how does it compare - under UV light - to normal 1033 ones?

As this is really a paper difference, the UV light could be a very simple and effective tool.

I will try to look later, I will be in a position to do so.

I did not see anything under UV which would be helpful in distinguishing the various papers; direct comparison is required. Whatever differences there are are essentially the same either way.

thank you very much. To understand it better: there was no difference that one could use like that the 1033a really is visible under UV light when you have like 20 stamps of 1033 and one 1033a?

If you have 20 of one and one of the other it should stand out pretty clearly in natural light. But the wet and dry printing complicates things. And of course it helps to have seen them before.

The thing is just, would it help to put them under UV light, so is there some little hint to say from 20 stamps, ok this one or two could be a candidate, from looking under UV light, and if yes, what would it be?

It would be the same things as discussed above when seen in normal light.

I don't have the stamp you are talking about, but I do have several UV lights, and I would like to share this;
UV light is actually a spectrum of different wavelengths. Certain wavelengths will give different results when shone unto the same surface as other wavelengths that give other results. Also, only specific materials are bioluminescent (glowing under UV light) or UV reactive (showing a different colour), if the paper in question is neither, there will be absolutely no difference under any wavelength of UV light. You will get different results using different wavelengths, so even if you had "a UV light", it wouldn't necesarily be conclusive until you have tried other wavelengths. Ordinary paper tends to just reflect UV light as a pure white colour, but I wouldn't know anything about this one.

A bit brighter than the regular paper, but that's visible at any time. If a paper is supposed to be a particular color, then UV is very good at showing that. The violet and green proprietaries come to mind. It's also good for telling the true colors of stamps. And cleaned cancels, of course. But it has its limits, just like everything else.

The question of 'Silkote' paper having any characteristic under UV light different than what the Bureau ordinarily used, is a good one. Some msgs have clouded the issue with, good intentions aside, more generalized "helpful hints" that do not apply to the 2c Jefferson printings (in 1954).
... UV light for hobby purposes is really in 2 different bands, "black light" (or Longwave UV), and shortwave UV. As general background, note shortwave came along for serious study of U.S. stamps only as of 1963, when the USPO started Luminescent Tagging program to apply phosphorescent compound to stamps as an overcoating (to trigger new machinery handling orienting and canceling letter mail). (Also by 1963, a few other nations were already testing or using compounds on their stamps detectable by shortwave and/or longwave.) Much fewer compounds relating to paper (or stamp ink) react at all to shortwave (intended or not), compared to longwave. I've never run across use of shortwave on U.S. stamps issued before 1963 to detect anything (erased cancels, etc.) but it cannot be ruled out.
... Longwave UV is known as a test to try at least as far back as late-1800s printed U.S. stamps (first postage dues, some banknotes), to reveal luminescent inks on some printings vs. other printings of "same design" issues. It is also used forensically to look for erased cancels, concealed repairs, thins, and other disturbances not visible in ordinary light.
... To the 2c Jefferson: all sheet stamps were "dry-printed" on Cottrell presses. Issued Sept. 15 1954, sale of Silkote sheets 3 mos. later means there was hardly any chance of a change in ink between Silkote paper print run and millions printed on plain paper, all subject to pressmen mixing/stirring ink used. Focus should be on the paper, and research into 'Silkote" treatment used if available (calendering, coating, brighteners etc.; I am not a paper-making expert).
... I asked a popular internet browser about optical brighteners being added to paper, and part of result was: " Indications pointing to the mid-1950s as the industry start date for the incorporation of optical brighteners are strong though largely undocumented."
... To laypersons like us, learning to be our own expertizers with tools at our disposable (e.g., stereo microscope), what you're essentially asking is a straightforward comparison report from someone who has examples of both paper varieties, of what can be distinguished with those tools like UV lamps and microscopes.

Long wave UV is quite useful for looking for paper varieties. I have cataloged hundreds of US stamp printed on paper varieties, especially on modern stamps. As stated by stampsOnMail using the generic term UV light is not specific enough. Unfortunately I don't have any Silkote versions to compare against.

As stated above, it is very useful for modern issues, but not useful for those before the early 60's. I was fortunate to have multiple examples to look at, including a genuine silkote paper example for my statement above.