Paul just my 2p worth paulsnap-at-dircon.co.uk (Paul Webster)::2/7/04::6:41 pm:: GMT-0000
>Hi, > a quick question , an ex assistant of mine who has gone digital is having >problems with a printer (person not machine) who is supplying grey/dirty >proofs from digital files and of course blaming her and her profile and then >charging for retouching and requesting raw files to work from. Am I mistaken >in believing that they have got their dot gain figures wrong and that this >is causing the problems? maybe, BUT: to imagine that dotgain is responsible for these problems, when it is only one of many possible factors, is a bit risky. It's a very simplistic view I'm afraid and there is no practical way to account for it in an RGB file anyway. Be aware that sending RGB to a printer who has problems using it is a real can of worms. Proper use of icc profiles to make press ready CMYK obviates the need for dot gain calculations anyway, it just becomes part of the printer behaviour as defined in the profile. (dot gain is now usually called TVI - tonal value increase). so: does he heed or discard the embedded profile does he have a proper policy for opening RGB files? one so often sees the cursor hovering over the <discard embedded profile> button it's scary. does either party (assistant or bureau) colour correct on a well calibrated screen does either work in a suitable (i.e. proper lighting) environment so he sees a screen correctly did the printer have an ACCURATE guide print supplied with the file (i.e. a guide print which truly represents file content and is within a reasonable CMYK gamut) did he maybe even cause the problems by adjusting the colour of the file maybe you should ask how both have Photoshop set up (what CMYK preset, option to preserve embedded profiles?) and send the repro guys that type of CMYK with a good guide print in future, or at least for a test. it was with all these issues in mind that Thomas and I - along with the committee of Bob, Mike and Adam (and you were involved yourself I think?) toiled to try come up with standards photographers could adhere to and be certified on. That initiative withered on the vine long ago. Well, ISO / FOGRA / ECI have now done it for us. We currently have the technology to make ISO certified proofs on a well set up inkjet printer, and to certify those proofs by measurement of a media wedge (colour strip) licenced from FOGRA and measured to strict ISO standards. On every proof if need be - This removes many of the problems inherent in file exchange, as long as the printer can print to (or near to) the ISO standard. It's the way of the future. see www.eci.org I have installed this setup for a few end users including a service you can all try out - with Jack Lowe for their new <colourhero> service which will soon offer more widely a high quality RGB-CMYK conversion and certified proofing service. [proper targetted CMYK conversion being perhaps the important part of the job ;-) ]. > > By the by I am having a similar problem with a prepress house supplying >dirty/grey proofs from adobe rgb .tif files viewed on my calibrated screen >and printed perfectly on my calibrated printer. Is this also a dot gain >problem or could it be someting else? see above Regards, Neil Barstow :: Apple Solutions Expert :: colourmanagement.net Consulting in Imaging & Colour Management, custom profiling, training, seminars implementation :: WE RESELL :- Gretag+eyeOne :: basICColor Squid, Display etc. XRite. :: GTI viewing booths :: Epson :: Proofmaster RIP + ISO Proofing solutions www.colourmanagement.net/ :: www.apple.com/uk/creative/neilbarstow/ =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
