Optical Brightneners
Optical Brightneners
- Subject: Optical Brightneners
- From: "Roger Breton" <email@hidden>
- Date: Wed, 19 Dec 2001 12:01:48 -0500
I am getting a greenish cast on my simulation from a Matchprint profile to a
Canon CLC printer out of a CMYK image in Photoshop (ConvertToProfile from
Matchprint to Canon - any Intent or CMM). Before getting into editing the
Canon profile, I tought I would measure the color of the paper (inexpensive
office-type Bond paper 20 lbs).
This is what I get :
X = 83.21 Y = 85.48 Z = 74.63
L = 94.09, a = 1.51, b = -3.60
I remember the discussion recently on the list about watching that b value
going over " 5 " as a strong indicator that a substrate contains OB. But I
am not sure what to make of this substrate having a b* value of -3.60 ? Does
not seem high enough ?
Here is what the Spectral Data looks like (from ColorShop). This is measured
with an X-Rite Digital Swatchbook - no UV filter, obviously). Is it possible
to conclude unequivocally on the presence of OB from this data ? Notice the
bump at 430nm and 440nm. (Appologize in advance for the unusually long
length of this message)
Roger Breton
Laval Qc
390 0.3166
400 0.5319
410 0.7472
420 0.8910
430 0.9441
440 0.9437
450 0.9275
460 0.9029
470 0.8874
480 0.8775
490 0.8739
500 0.8713
510 0.8613
520 0.8511
530 0.8480
540 0.8483
550 0.8479
560 0.8482
570 0.8517
580 0.8553
590 0.8549
600 0.8535
610 0.8545
620 0.8570
630 0.8604
640 0.8646
650 0.8700
660 0.8735
670 0.8684
680 0.8631
690 0.8645
700 0.8713