Does anyone know how I can obtain a real one? I am tired of wasting paper by making copies of old faded paper, then, cutting them down to do the many PPD readings I have to do. I tried looking on line, but, don't see where one can be obtained. I'd like something that I can possible place in my ID badge to pull out at any time. Or, I am hearing that some use calipers of some sort. Any resources?