Green-green decoder glasses often used for commercial purposes The purpose is to read red printed text that is printed behind green printed text.
This requires a very accurate chosen color for printing.
Often a chaotic patern is used to print over the to be discovered text or image.
Then you prevent to discover the picture without glasses.
The opposite glasses is red-red.
These glasses are intend to be used once or twice.
For that reason they cannot be returned.
Minimum order quantity is 4 pieces.