14 () posted 1 year ago by BuckeyePatr1ot 1 year ago by BuckeyePatr1ot +14 / -0 20 comments share 20 comments share save hide report block hide replies
It would have to reflect the exact wavelength to be 100% effective, but blue lasers vary between 400-500nm so somewhere between blue and purple.
Look into "Tekhelet" and "developments in the jewish community may also have played a role, such as the proliferation of counterfeit (indigo) threads which made the procurement of genuine tekhelet difficult"...