Re: Question re UV exposure for photopolymer plates
There is a risk of eye damage from UV if a photopolymer exposure light box
is misused, damaged or badly made. The risk depends on the UV wavelength
with the greatest risk at a wavelength of around 300 nm. I do not know what
wavelengths are used commercially but a wavelength of about 360 nm is
recommended for home made exposure boxes. This is most important as a lamp
with a wavelength of 300 nm would be about a thousand times more likely to
cause photokeratitis or cataract than a 360 nm lamp. Of course if you avoid
looking at the light or use the right type of safety glasses the wavelength
is less important.
While making your own box is not a bad idea it should be done with care. I
have been planning to make one for several years but have not yet got around
Plans for making your own light box are given in "Printmaking in the sun" by
Dan Weldon and Pauline Muir, published by Watson-Guptill, NY. Their design
seems to me to be safer and probably more efficient than the design you
The most important thing is that they specify blacklights with a wavelength
of 360 nm obtainable from a specialist supplier. Such lights cannot be
bought from a Supermarket here in Australia, only from specialised suppliers
so be very careful when buying your lights.
You may gather from the above that I am mainly a printmaker but I do also do
some letterpress printing but my "real" job for over 40 years has been
If your local library does not have "Printmaking in the sun" I could
probably scan the light box plan and send it to you.
Good luck with your home made box. I'd be interested to hear from you when
you've made it.