In the video I show how a cheap ultraviolet lamp, bought for 300 rubles on Aliexpress, can reveal the “black sheep” in your collection.
These counterfeit banknotes lay quietly in the collection for a couple of years until the moment when I decided to buy an ultraviolet lamp (well, just to admire the beautiful pictures in UV), and then I discovered high-quality counterfeits.
Of particular note is 100,000 rubles from 1995. Here the watermarks are of high quality and there is even a sewn-in metal thread! But still, it's fake! But for a collection, fakes are also not bad, I put them aside)