[A dual post to both Jeff & Darrin] Jeff Smith wrote in reply to Darrin Jenkins:
>> We've seen press proofs on three variations - using traditional CMYK inks, standard screening at 175 line, hexachrome CMYK only with stochastic screening, and true hexachrome CMYKOG with stochastic screening. << HI Jeff, interesting stuff indeed! So from the expected intended viewing distance for this work, how does the #175 and the stochastic compare - does the naked eye see any difference in dots or does it all just look contone? Does one look 'better' than the other, and if so in what ways? So, please do tell - what were the separation aimpoints for each of the three methods? Were the seps optimised for each condition or just a basic conversion to hex? Was the CMYK aimpoint specific or more general? Was the four colour HexCMYK ink job separated for standard four colour and run with hex process inks, or was this a custom sep taking into account the difference of the hex process inks? Then there is the true hex job as well... I understand that you are not involved in the prepress so I might be asking too much here. >> The results have been interesting. As you would expect, yellows, oranges and greens reproduce beautifully, the closest we've seen in nearly twenty years of designing for this client. The more 'normal' hues - variations of blues in particular, are a little harder to hit accurately. They seem a lot more saturated than traditional CMYK. A lot like the difference between Kodak and Velvia transparency films. << Thus the above questions for Jeff. Adding orange and green should not dramatically add that much difference to the richness of blues, but I have no personal separation experience with hex seps and ink hue differences over regular process etc. Where blues/greens/reds are critical, spot colour bump plates are often made to mix into the CMYK. ======= Darrin writes: > I asked him about the colour management / profiles for Hexachrome and he > replied that profile tagged files don't work for Hexachrome, and he will > have to do trial and error wet proof tests to get the optimum result. Only if they are using non ICC software, this does not sound exactly right to me if the above is a verbatim quote (but it does sound right coming from a unknown printer). > Does anyone know if this is normal for Hexachrome or if the is a best / > better way to print accurately the colours? > There is a 70,000 print run so rule out my 1290! Proofing an accurate solid spot colour is quite possible for many inks with some work, but as soon as you tint it or mix in other inks things are a lot harder! Hex or bump plate printing makes regular CMYK look like a reliable, consistent process that is a cake walk with no problems. Enter the wonderful world of hex at your own risk, prepare for major problems but also prepare for a big smile if/when it all works as planned. Regards, Stephen Marsh. =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
