Digital BW, The Print

Here is another scan of an Eboni BO print on semi-gloss (sprayed with 
Print Shield) that has dominant mid tone and highlight areas.  The 8 
bit, 72 dpi RGB scan is of an approx. 8x10 inch print.  There is also a 
1200 dpi scan at 100% within the small area outlined in red on the full 
scan.  The latter shows the dither pattern and dot size distribution.  
The dots in the highlight area are not visible to me in the full size 
print without using a loupe (however, sharper eyes may be able to 
discern the dots).  Also, there are two comparable scans of a QTR print 
on EEM of the same image made with a 50:50 blend of a warm profile and 
a sepia profile.  The inkset for the QTR print included MIS Eboni K, 
UC-LK, UC-LM, UC-LC, UC-Y, and MIS UT-LG (the Y position light gray, 
but I used it in the M slot).  Comparing the crops you will notice how 
much smoother the highlight areas are in the QTR print where the UT_LG 
ink was used.  For this particular image, I prefer the hue that the QTR 
warm/sepia blend produces, but either print is acceptable at normal 
viewing distances.  I'm still trying to get bronzing free prints on 
semi-gloss with QTR and the UT/UC inks, but so far the Print Shield 
spray has not been successful in completely removing the bronzing that 
is present when the light inks are used.  I'm hoping that the UT2 inks 
that Paul is developing may perform better.

72 dpi full image Eboni BO:
  http://www.homepage.mac.com/scho/skull.jpg

1200 dpi crop Eboni BO:
http://www.homepage.mac.com/scho/crop.jpg

72 dpi full image QTR:
  http://www.homepage.mac.com/scho/skull2.jpg

1200 dpi crop QTR:
http://www.homepage.mac.com/scho/crop2.jpg


Carl

On Thursday, January 8, 2004, at 11:13  AM, Carl Schofield wrote:

> I've been getting some excellent BO prints using MIS Eboni printed on 
> Epson Premium Semi-gloss with an Epson 2200 (2880 dpi, 20% dot gain 
> print space).  The prints need to be sprayed with PremierArt Print 
> Shield, both to prevent rub-off and to bring out the full beauty and 
> high dmax (2.2) on this media.  Right out of the printer, the prints 
> will look dull and flat because Eboni is not designed for RC papers 
> and sits on the surface (caution - will rub off easily at this point), 
> but after the Print Shield spraying (3 coats) the prints are durable 
> with no rub off.  The prints also exhibit no bronzing and no 
> metamerism.  The sprayed prints have a smooth, soft gloss surface very 
> similar to an air dried silver print and they appear neutral.  
> Densitometer measurements of the c, m, y densities of a 50% gray patch 
> were 0.65, 0.65, 0.65 for Eboni and for Epson Photo black 0.61, 0.65, 
> 0.67 respectively.  Below are links to two scans of sprayed, BO prints 
> (approx. 8x8.5 prints) on semi-gloss - one with Eboni and the other 
> for comparison (very warm) with Epson Photo Black ink (PK).  The Eboni 
> scan may appear to have a color cast (depends on monitor and browser 
> settings), but there is none in the actual print.  The PK print has a 
> chesnut brown hue, but no gloss differential and also no bronzing or 
> metamerism.  There are two possible negatives associated with the use 
> of Eboni on this paper.  One is a very slight gloss differential at 
> 100% black, but if a particular image has large areas of 100% black 
> this can be remedied with a simple adjustment curve to limit output at 
> 100% to about 98%, otherwise no adjustments are needed.  The second 
> negative is midtone grain that will be visible in large areas with 
> smooth gray midtone values.  Most of my images are busy landscapes 
> where this effect is not visible, but this might be a problem for 
> portraits.  I also tried using the UC inkset with both Eboni K and 
> Epson PK via QTR, but whenever the light inks (LK, LM, and LC) are 
> introduced into the mix bronzing becomes a problem on semi-gloss.  It 
> is attenuated by the spray treatment, but still visible to some extent 
> and disturbing to me in some prints (YMMV).  Neither the Epson Photo K 
> or Eboni K will exhibit bronzing when used alone and subsequently 
> sprayed with Print Shield.  The non-linear Epson driver also produces 
> some shadow blocking in the 95-100% region, but when necessary this 
> can be corrected by using a custom dot gain softproof profile and 
> making simple curve adjustments.
>
> Eboni:
>
> http://www.homepage.mac.com/scho/Eboni.jpg
>
> Epson PK:
>
> http://www.homepage.mac.com/scho/PK.jpg
>
> Eye-One scans of 21 Step wedges for Eboni and PK:
>
> http://homepage.mac.com/scho/EBPK.jpg
>