I am sorry but I am going to go out on a limb here and totally disagree with most of you that thinks it does not matter or that there has not been any good scientific research done. I hunt waterfowl quite a bit and know for a fact that they respond nagatively to uv glow coming off of white cotton sheets when some people use them as snow covers on blinds or persons. Birds will flare especially on a cloudy day like you would not believe if someone forgot to clean their sheets properly or they purchased foreign made blind covers with UV brighteners. I know some of you are going to naturally say that it is calling, or some other hunting fault but I don't care, I can tell you without a doubt that birds respond negatively to UV glow, I mean to the point of being funny or wierd and magically when covers are used minus UV glow the result is boom boom. Now with that being said I have been under the impression that the old studies and some more recent ones (I think the mose recent and elaborate was done by Univ. of Georgia) show that both birds and Whitetails lack a U.V filter and if that is the case you can bet your butt I will spend the 19.95 to be able to treat my stuff. If you have a question on how much glow you have then us a light and see. To me personally this is pretty cheap stuff when you think about all of the other things that we buy especially how much money we spend on camo, and oh yeah the scent control thing (now I think that is the gimmick). The reason that the old days of wool and such worked is because it was made in the good old U.S.A and UV brighteners were not added. I would also like to mention that I have had numerous occasions where I have been down wind and had camo from head to toe including my face, been behind good natural cover and deer would look right at me pick me out and run the other way.