Opinion on UV positive? ribbon bar

[vernon]

I recently purchased the following ribbon bar off our Forum from a member in Sweden. The ribbon and devices look alright , the tabs on the back have not been messed with, and overall the bar looks period. However, under UV light the white areas of all three ribbons light up. In the Forum post - Poll- is the UV light test the ultimate test- on page 6 in Andy B. Post- Andy shows some ribbon cloth under UV light that react similarly to the bar I have when this bar is placed under UV light; the white area of the ribbons light up . However, there is no purplish/bluish color associated with this light/ fabric interaction. Must a positive UV light test involve a purplish color associated with this glowing phenomena??? Does a lack of purplish color when white areas light up on fabric under UV light indicate a negative UV light test, i.e., not synthetic fabric?? Many thanks for your help with this question and time. Happy collecting.

[kenneth wolfe]

When you use the UV light on the ribbonbar put a modern sock or t-shirt on the side of the ribbonbar (make sure they are not to close) and go back and forth between the two. If the ribbonbar glows the same as the modern cloth then you have your answer but honestly I don't think this is a modern repro. It looks time period to me and if it does glow under uv then it was probably washed with some sort of modern cleaner.



Kenneth

[vernon]

Thank you

Thank you very much Kenneth for your comment. With modern paper and synthetic cloth I have noticed a purplish cast to the items under UV light. Is a purplish blue glow necessary for a "positive" UV light test ? This is a question that has not been expanded on in the great UV light article that was posted on our forum. In one of the posts in this article when detergent was purposely added to test fabric( insignia) only a white glow was noted under UV light. It would be great if another one of our experienced UV light experts on our forum expands on this one question. Your comments would be greatly appreciated. Thank you again Kenneth.

[J C Gray]

Remember that it is not the actual cloth that glows, but the phosphorescent chemicals that the cloth has been treated with and that not all detegents contain phosphors. Also remember that if you hold the UV light too close to the white object you will get a reflection from the lamp itself, which can cause the white cloth to appear as if it is glowing, giving you a false reading.

[deejay]

Please show pictures of the results next to modern paper; much better to judge then.

[vernon]

Thanks for your comments

Thank you Mr. Gray and Dirk for your comments. I have never taken a UV light picture before. I will give it a try with the ribbon bar when I get home tonight from work.

[vernon]

And the answer is---

Hello again. I got home and had problems with the shutter speed of my camera. Unfortunately, I was not able to take the UV pictures that I hoped I could post. However, I will try my best to verbally describe my findings. I hope my experiences will help answer a few questions that collectors in the future may have on UV light usage.

Initially I tested the TR ribbon bar in this post under UV light. The UV light source I used was from my Son's old CSI Crime Scene Kit. the UV light is battery operated and the tube shaped light is about 4.5 inches long. I tested the response of this ribbon bar against 75 other original German bars in my small collection. None of the bars in my original collection glow/light up under UV light regardless of the distance the UV light source is from these original ribbon bars (1 inch to r 5 inches). When I tested the TR bar against the other original German Bars the white areas of TR Bar glowed white under UV light. This white glow was pronounced when the light source was held 1 inch above the ribbon bar and still present but at a lesser intensity at 5 inches. When I compared this ribbon bar side by side with modern paper and white T shirt the glow from the ribbon bar was not intense as the purplish glow from the paper and T shirt. When I held the UV light source about 4 to 5 inches above the ribbon bar, paper, and shirt the glow of the paper and shirt were much more intense. A clear difference in glowing properties were noted between the paper/T shirt vs the ribbon bar. What does this all mean??? I am running out of room, so I will continue in the next panel/post.

[vernon]

Part 2 - and the answer is....

It would appear that a UV positive standard and the proper distance the UV light source is held above the items of interest is important in some UV light interpretations. For my UV light source and test conditions about 5 inches above the ribbon bar while using white modern paper or T shirt standards was sufficient to show that the ribbon bar was not "glowing enough" to be classified as a UV light positive bar. I guess my initial mistake was comparing the TR bar in question with good original bars instead of using a positive test standard and using an improper UV light distance above the ribbon bar . When I repeated this UV test using a known American ribbon bar made with synthetic cloth as a positive standard it worked well.
However, some old time collectors that I chatted with today have told me that a non synthetic fabric should not glow at all and it does not matter how far away the the UV light source is from the fabric. Hum- well that is disturbing, I thought we had an ultimate answer to this UV Light test question.
I guess some thoughts to this problem are 1. Use a Good positive standard to compare against - don't worry about white or purple color glow 2. Consider the UV light distance away from the test object 3. As many other collectors have previously suggested Collector experiences should also be considered in the final interpretations of whether an object is good or bad.

[keifer kahn]

Hi Vernon,


Dont blacklight under 12 inches from the item or you may confuse "glowing" with" reflection".
The "purple" is simply the reflection of the colour of the blacklight and not an indication of fluoresence or glowing.This purple effect is dependent on distance of the blacklight from the item and reflective sheen of of the item.(More shiny=more reflection).

If the item is truly fluoresecent then it will still be fluorescent even if you hold up the blacklight from the other side of the room.Where as a non glowing item will dissappear into the darkness of the room.

As for colours its the "intense " white we dont wish to see.
As for "White glowing" , fabric washed or cleaned with detergents containing phosphates (commonly obtained) will cause an item to glow.The glow is not as intense as fabric commercially dyed and will have a more subdued glow and may appear patchy in effect.

Regards KK

[vernon]

Thank you very much

Thank you very much Mr. Kahn for the great information on UV light usage. Happy collecting and I wish you Happy Holidays. Vern