UV light and SS decals

[Helmcollector]

here I am again, collective wissdom...
As a veterinarian I sometimes use an UV light (which we call a Woodlamp) to for instance determine if a hairless spot on the skin of an animal is caused by some fungi. Some of these fungi glow under an UV light.
Some time ago I posted some SS helmets. Most of these were considered fake decals. One was considered a real decal. So it came to my mind if there would be a difference if I shine an UV light upon them.
I do not think that I invented the egg of Colombus (an expression that might not exixt in English) but guess what....
The black runes of the real decal became extremely pale under UV light, while the others stayed black.
Perhaps worth trying for those who have one or more SS helmets (fake or real) if there is some truth in this story....Or perhaps my decal is infected wiith a fungi
Number 2 should be the real decal. Pictures in the dark not easy to make, but in reality it is quite obvious...

[thecyclist64]

Never come across this for determining the authenticity of decals before. UV light is normally used to determine medal ribbon authenticity, as post-war invented polyester fibres will glow under UV light, but cotton won't. This is not 100% authoratative, but does at least eliminate polyester/synthetic fibre ribbons as not being pre 1945. It is also the case that if a pre-war ribbon has been washed in modern biological washing powder, it will also glow under UV light if not properly rinsed out. I wonder if somebody, many years ago, tried cleaning the helmet with some detergent and this is why you have glow in the dark fungi on your decal.

[Helmcollector]

There are so many chemical substances and molecules that may show fluorenscence under UV light. UV light with higher energy is absorbed by some molecules and give back light with another frequency and lower energy, so another colour. I just wondered if there might be a substance in real decals abscent in most fake ones. Penicillin would not have been invented, if Fleming was not asking himself : 'is there a chance (although it is a very little chance) that these fungi on my petri dishes are slowing down the growth of these bacteria'. Unless checked on a greater scale, i do not take for granted that these are fungi on this decal.

[Airbornehunter]

I have collected American military patches for over twenty years and can confirm with absolute clarity that a UV light means close to nothing when it comes to cloth and more often than not leads people astray. At best it is a tool, not a crutch, do not use it as a crutch.

Towards the decal, best guess is the light is being reflected by the underlying layers on the decal. I have an authentic Quist M35 DD that came out of a flea market, it does not appear to exhibit the same characteristics as yours. I am not an expert on decal manufacturing but my general understanding is that they are made of different layers. If we think about these layers, the silver "base" layer on many decals is likely made of an aluminum or silver or similar based paint. Both of these metals are relatively inert when compared to other metals. As such, I would expect these layers to better hold up over time (in fact this is their exact purpose in modern paints). This may well explain why some decals lose their black, but maintain a lighter silver color layer underneath. Therefore, it would be more likely that there would be more reflection on a worn decal and by extension and obviously more reflection on an acid treated decal such as the one shown above. To this point, areas of partial damage on my Q M35 SS reflect, minutely, but relatively, more than the other areas which lends to this exact idea.

Just some thoughts ABN

[Martin3]

Hi,
Long time ago (not here) I suggested to build a database in which the findings were noted of original items response to UV light. I thought it would be a priceless source of info! But it seems that a lot of collectors were shy of testing expensive items and confessing some original items seem to react in UV. Which of course is quite understandable as too many people still see the UV lamp as a very reliable test.
It is all in the dyes used whether an object will react in UV or not, I was told by a chemist. Synthetic fibres were widely used pre and during the war. Like rayon, for instance. But the dye used on the fibers decides if there is a reaction to UV.
When it comes to paper items I consider UV as a helpful tool. Modern paper is often recycled and bleached. Now that responds hard in UV light! But again: the paper can be negative: the ink on the paper can be positive. And postwar paper, especially early postwar paper, is ideal for counterfeiting purposes because it is UV negative.
Original helmet decals I found out, do react under a UV light source. Often a soft, purple glow. But not something to wear shades for.
All in all: UV is one of your tools. Like the burn test. Like smelling and sometimes tasting. Often it is just that one connecting thread at the backside of a fabric badge that lights up and makes you suspicious. That is when the forums and books come in.
To know your originals is the best way, I was assured by befriended collectors. The tools are nice, but can't beat knowledge.
If the lamp would be considered watertight, the bad guys will respond directly with UV negative materials.
Long story, is there a conclusion?
Ehm, yes, do not trust your lamp when it comes to telling the good from the bad decals. You probably will be taken.

[Putzi]

As far as I remember the helmet black runes will turn slightly green under UV light.
I don't have any helmets any longer, but the clever "bad guys" certainly already (recent years) adjusted their fabrication methods for SS cloth to be non UV positive, the older copies still light up like a Christmas tree on a dark night.

[Kohima]

The database is a nice idea, but there are far too many variables; everything would have to be tested with the same lamp, to ensure some kind of control... but which lamp?

[Helmcollector]

Which lamp ? A lamp that emits UV light.... The range of the wavelenght of the light is between 100 and 400 nanometers. You can buy them on the internet for 20 euro....Also used for checking if banknotes are not false : in the euro banknotes there is a hidden text only visible under UV light.

@martin3 : what is the 'burn test' ?

[Pauls1970]

I was on the understanding that the green/yellow hue given off by a helmet decal, under a UV light is down to the lacquer used on the face of the decal.
Paul

[Martin3]

The burn test is an old method to test if the material is wool or a synthetic fiber.
You could light up the whole item you are testing but better peel of a loose, frayed thread. Gently move the thread to an open flame and watch what happens. If it wrinkles away, it is melting and you are probably dealing with post war polyester fibers. When it burns gently, it probably is a wool or cotton fiber and it stands more chance. Again: it is a little helper and not waterproof . Experienced fingers start to feel the difference between wool and synthetics, but you do need to feel a lot items to build up the experience. Which is often quite impossible of course.

When you pay attention to it, you will start to see that a lot of cut-from-the-role eagle insignia are hard to the edges. That is because when the seller cut if off the role, he quickly run a lighter across the edges. The melting of synthetic fibers happens very fast and will stops the material from fraying.

Needless to say I STRONGLY advise against burn testing decals. Although you could imagine the modern water transfers behave differently than the old factory applied original ones, when exposed to an open flame. Could be an interesting research project...