With a black light test, new cloth materials have plastics in it and the color will reflect back a lot brighter than on ww2 era cloth with no plastics. The same with the burn test. I found a loose piece of thread and cut it off and tried it. You get a piece and burn it. If it shrivels up or melts then it is bad. If it turns to ash it is good. You can use a lighter or matches for the burn test it doesn't matter. A black light can be found at a hobby shop or ebay because a black light is for telling if collectible money and stamps are real. The ink shouldn't shine back I believe on these.....