Posted By:
MWDavid --
Actually that is not always true. I have conducted some tests using a simple black light source and a multiband UV 115 V Mineralight lamp. The $5 to $10 black light only operates over a limited area of the UV spectrum whereas the multiband lamp had a range of 254/366 nm. Not all alterations would be visible using the former UV source. The difference is distinct and remarkable. Using the right detection methods, NO alteration is undetectable.