On Wednesday 15 September 2010 22:56:07 Jon Cruz wrote:
On Sep 15, 2010, at 10:45 AM, Jonatã Bolzan wrote:
They only accept files using CMYK colorsystem. Usually we send in CDR (CorelDRAW) format for film (photolith). When it is a CTP service we send in PDF format. When I use Inkscape to draw the art, I need to use the extension "Export TIFF CMYK". Then I generate a TIFF of all the work, put in Scribus and generate a PDF in CMYK. Never got problem with that. When I need to generate PDF with CMYK values for vector graphics (text for example) I have 2 options: from Scribus import SVG and convert the RGB values to CMYK using the plugin "rgb2cmyk" or in Inkscape using the extension "Export PDF CMYK".
But the *HUGE* problem is that there is no such thing as "the CMYK colorsystem". If a print shop is going to produce the same color from one week to the next, they need to be working in a *specific* CMYK colorspace.
In my case, I need to get the exact value of CMYK that I put in Inkscape into the off set plate. Could some ICC profile help me in it? My experience says "no".
I think what you really *need* is to get consistent visual output, not consistent ink saturation. There is a very subtle difference, but one that means if you do a reprint on a job a month later the newer copies will match the original ones.
I don't find the extension "Export TIFF CMYK" on Inkscape 48. Is that a download somewhere? Does it convert to bitmap?
Ink saturation is however important. "Rich Black" on some palettes has a total saturation of 260% but LSI, always being difficult, insists on no more than 240% for any color including of course Rich Black. I use a special ICC profile that someone cobbled up for me on the icc_users list and based on SWOP Coated that limits total ink to 240%. In turn in Scribus and using the Scribus Open Office Palette I create a Rich Black of C=60,M=40,Y=40,K=100.
All the presses I use are digital, including of course LSI.