Digital BW, The Print

Steve Kale wrote:

>
>>B&W mode suggests that something like that is used.  I bet it actually
>>makes an RGB file of the Greyscale in the driver again like the Epson
>>drivers do with CMYK files already.
>>    
>>
>
>So they convert CMYK to RGB and then back to CMYK?
>  
>
Correct, it has always been that way with Epson's driver.  That's why so 
many are disappointed when they send CMYK to an Epson driver.

>  
>
>>The toner addition can overrule the
>>CM so sepia etc remains possible..
>>
>>Reading the information again I start to doubt whether it actually has
>>linearising features in the driver. It mentions linearisation at the
>>factory 
>>    
>>
>
>For the wide format models only.
>
>  
>
>>and combined with Atkinson like profiles that would be good
>>enough for most but not for the long run and third party papers. Custom
>>profiling can take care of smaller linearisation shifts in time.
>>
>>Better keep QTR on your system if it isn't working nice on B&W.
>>    
>>
>
>As I understand it, QTR effectively takes single channel input and the
>separation into multi-channels occurs according to the ink selection and
>partitioning process conducted when the curve is made.  Is there any
>advantage to taking a three channel approach within the document and running
>the printer as a(n extended) CMYK device?  I suspect not but I as I said I
>am in the early stages of learning about CMYK separations from RGB....
>  
>
I guess that when your driver is very much RGB based at the input side 
it may be easier to use that for B&W output as well. And many digital 
cameras have RGB output for their B&W takes. There's no other advantage. 
Greyscale has smaller files, should process faster but it may take more 
time to write separate partioning curves for each resolution and paper 
combination than lending part of that from the color paper settings and 
CM data.

>Another point:  wouldn't it be nice if Epson upgraded the 2100/2200/4000
>inks to the new formulae, albeit without the llK....perhaps wishful
>thinking.
>
>  
>
The very few times that Epson upgraded older models showed that either 
it was too expensive for what it delivered: 7000>7500, 9000>9500, didn't 
get much interest: 10000 (1280) LM and Yellow dye inks for the 7000-9000 
or the upgrade period was so short that nobody knew it was possible 
10000>10600 (only John Dean knew about it :-).

Ernst