Subject: Is there a paint that is invisible in daylight except with glasses?

Most if not all paints reflect some color and absorb others.  In natural 
sunlight, identifying colors or paints appears to be rather simple thru our 
sensitive eye brain interface.  At this time in history, marking or identifying 
specific structures, ie. metals, plastics in daylight for content is limited to 
what seems unaided visual physics.  Perhaps these items could contain pigments, 
not harmful to humans and plants that are visually color different with the aid 
of some type of inexpensive goggle or optic lens in natural daylight.  In day 
light frequescies of the sun, stimulation of these invisible colors could 
identify the material make up.
PVC one color, polycarbonate another, brass still another...and so on.

Accurate separation of waste or discarded material could maybe sorted easily 
thru the use of special glasses in the daylight. Detection of stollen goods 
invisibly marked could be identified in natural daylight with the use 
of  "special" glasses. Artificial lighting such as 'Black light' or infra red
would not be necessary...just the glasses and pigment and the sun.

Re: Is there a paint that is invisible in daylight except with glasses?