>> It was a special image and needed two different conversions and blending before sending to press <<
One could perhaps get away with a single conversion, using a heavy GCR TR001 aimpoint - but: * In colourful images, heavy GCR is not good as we do not wish too much black in our colours. * In the case of Ellie's image, the hero was dark brown/black wood - so I decided to run with a UCR separation which is traditionally uses the lightest amount of black (GCR can be considered a subset of UCR). As I mentioned to Ellie, there are often compromises in a print job such as this - is the neutral gradated background the most important aspect of the reproduction, or is the hero...or the whole image (perhaps not easy). A complex image would not easily lend itself to blending two different GCR separations into one - but in this case it is easy to isolate foreground/background elements so one can be more exotic. In a different case I may only make one CMYK conversion which is heavy GCR, it would depend. >> and there was a failing on the part of the printing company in not recognising that this was a special image and should have been treated differently or expectations managed. << Some printers just say "give me CMYK" without any thought. Some may understand that ink and paper play a part and may have a custom or standard ICC profile aimpoint for coated and uncoated work. It is the rare printer which is clued into GCR internally or externally for their clients use and education. 95% of jobs that these guys print may be fine with the GCR offered by the Adobe v2 SWOP (TR001) profile. Ellie's job is one of the rare ones which has a four colour neutral _gradated_ background. Other rare cases are comics or coloured line illustrations, maps or screen captures. It is always the exception to the rule which will trip you up. >> The profile they advised me to use was incapable of handling this image satisfactorily for all parts of the image. << Profiles and Colour Management are fantastic and do a lot - I wish they could do more. >> Interesting that he took all the blame. I spent some time explaining what Stephen had observed about the file and the GCR etc, but he was not (I suspect) on the same wavelength. I find it hard enough to follow myself, as I feel a bit out of my depth. I feel that I am beginning to understand it, though. << As I said earlier, some printers are good with prepress - others are not in this area. It is stuff directly related to presswork, so they should know about it...but until recently there were trade colour houses and prepress shops which took care of all this stuff. Now that these shops have mostly been pushed out of the market, prepress has either changed fields or moved into printers or design studios, ad agencies etc. If they are getting confused, just stick to monosyllabic words, grunt a bit and say "more CMY and less K = bad ... more K and less CMY = good ..." as long as the main hero image does not suffer... >> Anyway this is where we stand now. I will prepare this file and we will end up with 5000 postcards of the same image! (already it seemed that 2500 was more than necessary). But this has been an interesting learning experience. << The same image, but separated and prepared rather differently than the first print - so not the same at all. I imagine that their will be a great difference between the first and second print - for two reasons: i) The different separation methods ii) The printer will now be paying more attention to this job It remains to be seen whether my suggestion of heavier GCR for the background will provide the desired result that Ellie and Co. require or that the pressman may be concerned with the heavy K plate if he is used to traditional light K plates. I hope that results will be satisfactory to all. On the main "hero" image - I am sure that this will reproduce better than before. The Chromix SWOP profile has a contrast boost in the perceptual transform, which I usually do not like. But in the case of a very dark object - it is very nice and ads a little bit to the final print over the Adobe SWOP v2 profile which does not have such a contrast kick. My only concern here is that due to more black in the background that the hero may darken up a little too much than previously. Just to be clear here - one must do a little bit of research and work to attempt to emulate a proper profiles grey balance, such as the SWOP v2 (TR001) Adobe CMYK profile when converting using the legacy Custom CMYK command of Photoshop. By default the old separation tables stock/inksets do not match the ink/stock found in proper ICC profiles commonly used today. It should be possible to emulate Euro inks/stock grey balance, but I have not attempted this yet. It is also possible to alter an existing CMYK grey balance to a new condition, but in this case reseparation was the best move. Also of note, adding "smart noise" to the gradated background in this job of Ellie's may be a good idea as well (she did not mention any banding in the final print, so this may not be an issue). Smart noise is noise that is luminance component only (no hue/saturation component) and that the noise is not introduced into the extreme highlights and shadows. Regards, Stephen Marsh. =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
