U of S | Mailing List Archive | alt-photo-process-l | Re:Epson R2400 inks density

Re:Epson R2400 inks density


  • To: Alt-photo-process <alt-photo-process-l@usask.ca>
  • Subject: Re:Epson R2400 inks density
  • From: Erich Camerling <e.camerling@tiscali.nl>
  • Date: Fri, 01 May 2009 15:38:53 +0200
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Dear Alberto,

Thank you very ,very much for the given data about R2400 inks.(Ultra Chrome K3) I suppose it are the same inks like Ultra Chrome Hi-Gloss but with 3 black inks.Then these data are also useful for the R(1)800.May I make some corrections ? UV-A region is from 320 - 380 nm.The minimum absorption of the yellow ink is at about 340 nm (not 440 nm),M and C have their maximum at 320 nm (not 420 nm) in the UV-A region.
My UV-A lamps (Philips Cleo) have their peak at 350 nm. and the points of 50 % of the peak power are at 330 and 370 nm. Because the highest sensitivity of [Fe(C_2 O4)3] 3- ( the sensitiser) is in the 313 - 365 nm region for Pt or Pd (see The Journal of Photographic Science.Vol.34. 1986 page 13 - 25.Michael J.Ware : An Investigation of Platinum and Palladium Printing page 15.Table I :
Wavelength in nm.versus Fraction of Light Absorbed:
313 - 0.99
365 - 0.92
405 - 0.35
436 - 0.073 for Pt

313 - 0.89
365 - 0.90
405 - 0.32
436 - 0.063 for Pd )

it is not useful to look at the curves above 380 nm. for Pt or Pd. For silverprinters it would be very interesting if you could complete the data with the curve of Pyro stain.(stepwedge with and without Pyro)
Kind regards
Erich

For readers who don't know the meaning of "logarithm" (log10)
A=0.0 means transmittance is 100%
A=1 10%
A=2 1%
A=3 0.1%
The yellow ink has a transmittance(T) of ~3% at 350 nm.(A= 1.5) and T=1% at 370 nm. (A=2.0)
the cyan ink has a T of 0.05% at 350 nm.(A=3.3) and T= 0.3% at 370 nm.(A=2.5)
So the M and C inks are the best blockers in this case at 350 nm.