On 2007-10-04 21:47:18 -0230, tacit said:

In article ,
macbook <privaty please> wrote:

The RIP does resample digital data into spots and dots when it creates the halftone patterns that are set at the perimiters of the printed job. It even resamples vector art into spots (1200-2500)

Actually, these days most imagesetters are 3600 dpi. I've seen 2400 dpi imagesetters, but never 2500.

You in North America or Europe? Different. 2450 / 2500 are pretty common but in different areas.

depending on
what's the best for the halftone screen and the paper/ink etc. Some presses are even digital right to the plate. Might have heard of them... they are called computer to plate or direct to plate.

Yes. I service platesetters, among other things (I think that's the term you're looking for).

You got it, now the important part is to find out if
platesetters/imagesetters handle information digitally or analog. Once you answer that, you'll be on your way to what my rebudle is all about. :)

There's
even some that have direct to press ( right on the cylinder). It's all digital until it outputs to film or the paper. It's really quite interesting stuff if you go beyond the "how to books" and the experience of most agencies. Take it a bit further than easy.
The optimal resolution isn't twice but 1.5 ( twice is just the standard used by ther bulk of graphic designers but it's over compensating. 150 x 1.5 = 225 is the true optimal.

Where do you get your information? Who told you that that is "best"? I ask because, you see, it contradicts everything currently known about data quantization.

Maybe I should ask you the same. But the true answer is there is no true answer, This topic is not black and white, and most of us are in disagreement. (as we are ). For my part, I've tested this theory myself and will continue to preach what I've seen side by side comparisons. I've sent files to sheetfet and offset presses using various DPI, Color corrections and sharpness. Plus I've also tested what subjects look better with GCR or UCR seperations since most presses save money on GCR and will always notify you to use GCR. Of course GCR is safer, but it's far from the best solution for quality on certain subjects. As far as DPI is concerned, 300 is MOST definetely over-compensating on many presses. YES, there are some new presses out (waterless) etc. that can handle higher DPI but most of them out there will still set there RIPs to under 150 LPI or less. This means that all your glorious images that you've sent at 300dpi will be stripped of some information when the RIP program calculated where to put the spots and halftone dots. In a matter of fact you could have send them 225 DPI and it would be the same.

If you don't get this, it's all o.k. It doesn't make much of a difference. It would make a difference if you send files with the Resolution to low, but to high is quite alright. My issue is with the fact that you've stated that there is no resampling, in fact the RIP must resample in order to use the lower halftone setting. Or in other words, it drops information when this process happens.

This stuff is complex :)
--

Cheers,
MacBook

Wolf

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