To make another quick “Lumen” test for UV-blocking properties of an inkjet transparency, printed with an Epson 3800, we exposed a sheet of over-age Emaks paper through the printed film (as in the previous test on 28 Feb) in our UV-box for several hours during two days. The result is below (the color shift is quite interesting):


There really is only one possible patch producing the lightest tone on this paper, corresponding to this particular “neon green” on the transparency: 0, 255, 170.

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How will laser printers perform at the UV-blocking test then. Not very well, we can tell you:


None of the color densities that the printer (Canon iRC3200) could output on it’s general use OHP transparency can’t hold UV-light, it will penetrate through all the hues almost equally well.

Now we are just waiting for the sunny spring days to come soon (with light rich in UV), so we can load our printing frames and leave them outside to expose some Lumen for us … 😉