Hi Matthew matthewward-at-talk21.com (matthew ward)::20/10/04::12:21 pm:: GMT+0100
>I have just got off the phone from a large prepress house because some >tear sheets have rather more black ink on them than is ideal. (Like >the paper is buckled where the dark image is.) > >They originally stated that euroscale coated v2 would be fine. >Apparently they have a company policy to respect the RGB profiles but >strip off all CMYK profiles to keep the total ink limit to 300%. >(AFAIK Euroscale is 350%). Does anybody know how widespread this >behaviour is? I think it's quite widespread, since the default CMYK in Adobe's European prepress defaults is Euroscale coated. This seems to mean that those who look at Photoshop with some care will choose Euroscale, whilst those who just install, and take defaults will probably use SWOP. When a cleint says <just give me CMYK> it is often a recipe for some phone calls later. for European press work it's actually worth looking at: http://www.eci.org/eci/en/060_downloads.php FOGRA have done extensive work on characterising typical European printing processes. I'd advise you to download the up to date ECI_Offset_2004.zip 4788 KB 2004-06-01 These ECI profiles are made from the FOGRA datasets. These were obtained by experts from various presses set up to optimum repeatable performance as in ISO 12647-2. Thus, the ECI profiles can often provide a much better characterisation than Euroscale Coated which is: 1: too high an ink limit for many processes 2: made from a cromalin proof, not a press run However, one warning. The graybalance in the ISO/ECI profiles is a little different to Euroscale and this can lead to issues depending how the press is run. Ideally, we'd all be sending work to presses which, when of a similar type, were run the same , maybe to the <ISO standards>. The softproofing and in house inkjet proofing would then be very good ways of predicting press output. Even a relatively humble Ultrachrome Epson can do a great job wheh set up properly with an accurate RIP. This is what many pre press houses are moving over to, and given ICC with good profiles a photographer can easily produce ISO certifiable proofs to accompany his important files. We've provided this solution to a lot of operators. It seems to me to be part of a good professsional photographer's responsibility [even if supplying RGB] to look at the CMYK preview and keep an eye on gamut warning. RGB colours which are far outside CMYK gamut will often prove problematic when the conversion to CMYK is made. The sensitivity required during such a conversion is one very good reason for a photographer to take charge of making CMYK where possible. Especially in these days of automation. However, good proofing, good softproofing, good pre conversion gamut warning and good conversions all depend on reliable information about the press. As others have written, sending out an RGB file can be like providing a colour negative, you created that lovely [RGB] symphony for a 30 piece orchestra, but now someone needs to adapt the piece to work with 3 saxophones, a triangle and a Euphonium or 2. It takes care, good ICC worklflows can really help. I'm hoping for a wider acceptance of the FOGRA, ECI, ISO initiative. It seems to be happening in Europe. It would make everyone's life easier wouldn't it. >And what on earth are we meant to do when the client specifies CMYK. >And yes I did supply RGB (Adobe 98) as well before anyone advises me to ideally you really do need to have a good ICC profile to describe the press, and to take care of inklimits, black generation and colour (grey) balance. more research: interesting piece on ink: http://www.fogra.org/xpdfs/FOGRAextra9.pdf general: www.fogra.org www.eci.org www.ugra.ch www.bvdm-online.de [German] www.altonatestsuite.com Best Regards Neil Barstow Consulting in Imaging & Colour Management http://www.colourmanagement.net/ http://www.apple.com/uk/creative/neilbarstow/ =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
