Digital BW, The Print

Olivier wrote:
> Having read all posts (thanks) and thought about it, I came to a 
> possible workflow based on not using IP and trying to actually 
> simulated ABW.
> 
> Can someone comments on the below :
> 
> All is done in AdobeRVB, G2.2 working space.
> Colored parts of the image and BW ones are separated onto 2 
> doccuments.
> 
> BW doc is converted to a BW profile in the intent of retaining strict 
> greyscale values and profiling the output. This is then turned into 
> RVB. 
> To cope with "neutrality" (whether paper tint, ink tint...) and 
> toning capability; a first simple "fill-in with color" layer is added 
> with a fusion mask of the RVB channel (that gives a greyscale mask of 
> the image to the color layer). First color is thus appplied only to 
> highlights and adjustable with opacity variations. This could also 
> serve for toning. A second layer of the same nature (fill-in with 
> color) is added with a negative of the RVB fusion mask to possibly 
> colorize shadows and adjust (if needed) tone variations in this part 
> of the image. 
> 
> The BW image is now RVB, BW-profile-converted with capabilities for 
> toning in all needed ways. That should simulated ABW (and eventually 
> IP) to the closest way I could figure out.
> 
> RVB doc is simply converted with a usual color profile.
> 
> BW doc is paste onto the RVB one (both are RVB tagged), and this can 
> be printed "same as source", icm off. Softproofing is no longer 
> available, but I can't find a way of preserving it either than full 
> color management workflow which will not allow BW profiling from 
> which I expect greater linearity and smoothness of the greyscale and 
> fine toning capabilities with the layers.
> 
> Thinking as much as I could, I'm expecting this would be coping with 
> all the profiling issues, neutrality-toning ones, one single pass, 
> and contrast balance of the all output. 
> 
> Where I'm unsure (because I have limited knwoledge of it) is the 
> coping of GCR. My undertsanding of Tyler's post was that with a BW 
> profile I'm to expect a more contrasty BW part than RVB part (black 
> generation being stronger in the BW part ?). If so the color layers 
> would eventually "hide" this.
> 
> Please comment/correct if you feel like it.
> 
> Olivier

Olivier,

RVB,  exchanging Green for a Violet ?  :-)

I haven't read it carefully but there's no chance to 
circumvent the paper settings in the RGB profiled Epson driver 
system. Based on that you will always get the same black 
generation + composite grey elements for both color RGB and 
Greyscale images if printed in one run. What you are thinking 
of would be possible in a CMYK profiled RIP. It would also be 
possible with the Epson driver if you split the printrun in 
two: one for the greyscale with ABW (still using more 
composite greys though than QTR but less than in Epson color 
mode) and one for RGB color images.

Given the complexity of your approach I think you will get 
more predictable results with a good profile and using RGB B&W 
images like C.D.Tobie suggested in his first message. My 
comments were sketching an ideal RIP solution that doesn't exist.

Ernst







                    --
           Ernst Dinkla


www.pigment-print.com
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