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All pigments (with the possible exception of things like
carbon black) can be faded by strong light, particularly UV.
In general, the pigment industry has striven to minimize
this effect, producing pigments which are as stable as
possible and do not easily photobleach.
should be possible to produce pigments
which are particularly prone to photobleaching.
If so, there is the option to produce a range of printer inks
which could be erased by brief exposure to a strong UV
This would enable documents to be erased, and the paper
[xaviergisz, Jun 23 2014]
blue wool scale
[mylodon, Jun 23 2014]
The perfect inks for this [hippo, Jun 24 2014]
||// All pigments (with the possible exception of
things like carbon black) can be faded by
strong light, particularly UV //
||Disputed. Pigments based on metallic
carbonates and oxides are extremely
resistant to UV bleaching. Stained glass
retains its colour despite many centuries of
intentional eposure to intense sunlight. Loss
of colour is usually due to leaching of the
pigment by mildly acidic rainwater.
||Living near an ozone hole has shown me that
bleaching is pretty common and not related to rain
anymore then gnomes crawling into your house at
night, painting whiteout on your couch. I would be
curious as to the implementation of this photo-
eraser. Blue jeans fade quickly; why is indigo so
prone.. Or is it just to acid washing?
||A number of early inkjet-printer ink formulations tended to fade with
time. Just bring them back.
||//Disputed// Fair point - metallic salts (and
inorganic compounds in general) tend not to bleach.
However, organic pigments do.
||Yes, but you wrote "all". If you'd said "all organic pigmernts" we would
have let it pass.
||What happens to paper under intense UV?
||Many printers don't deal well with simply flipping the
paper over and printing the back side, since the
paper is no longer perfectly flat and uniform.
||//Yes, but// Yes yes, [8th]. I sometimes like to
make mistakes to avoid giving the impression of
infallibility, which many people find disconcerting.
||//What happens to paper under intense UV?//
Enough UV will damage it, but it would need to be a
lot. I think dyes could be developed which would
bleach with a fairly low UV dose.