At 11:51 -0400 22/6/12, Stuart Rogers wrote: >Isn't it more complicated than that? (I'm no colour expert; I've just had >some confusing and *bad* experiences trying to deal with colour through >FM/Acrobat/Windows.) > >Pantone does specify printing inks -- but isn't it the case that results also >depend on the specification of the paper the inks will be applied to?
Stuart, you are absolutely correct. I was trying to keep the explanation simple. In fact there are many Pantone libraries, each fine-tuned to the actual printing process that is going to be used (solid (spot) coated, solid uncoated, process uncoated, process coated, pastels and so on) - my copy of Illustrator lists 10 different Pantone libraries and InDesign 13). I only know as much as I need to know to take books to press, but my contact with professional printers has led me to believe that their area of expertise is certainly no smaller than ours as document creators, but orthogonal to it. As a digression that might also be helpful to Susan, in FrameMaker you will also need to specify whether the color is 'spot' or 'process'. This refers to the printing process: a spot color is (or was, traditionally) printed using a single plate and a premixed ink, while a process color is printed using a four-plate process, mixing the color from the relevant levels of cyan (C), magenta (M), yellow (Y) and black (K), much as a laser printer does. Originally, these would be printed using, say, offset lithography and four (or more, for art work) actual physical plates, but this distinction has been blurred by the advent of machines such as the Xerox iGen, which is basically a giant high-resolution laser printer. To illustrate for physical print, assume a book that contains black and a single color, such as is often used for textbooks. If the single color is specified as a stop color, the resulting PDF *should* request only two 'plates', one for the black and one for the color. If the single color is specified as 'process', the resulting PDF will requite four plates, mixing the single color from cyan, magenta, yellow and black. This is often not what is required. Here is an example of the sort of thing I mean: <http://www.amazon.com/Java-Actually-First-Course-Programming/dp/1844804186/ref=sr_1_5?s=books&ie=UTF8&qid=1340448980&sr=1-5&keywords=mughal+java#reader_1844804186> This book was done in FrameMaker using just black and a spot Pantone color. There is a good page on Pantone in Wikipedia... 'One such use is standardizing colors in the CMYK process. The CMYK process is a method of printing color by using four inks - cyan, magenta, yellow, and black. A majority of the world's printed material is produced using the CMYK process, and there is a special subset of Pantone colors that can be reproduced using CMYK. Those that are possible to simulate through the CMYK process are labeled as such within the company's guides. However, most of the Pantone system's 1,114 spot colors cannot be simulated with CMYK but with 13 base pigments (15 including white and black) mixed in specified amounts.' In the latter case, assuming two-plate printing, the printer (human) first mixes the Pantone spot color ink from the base pigments, then applies it in the printing process from one plate. However, it's important to know what printing process will be used; if the printer (thing) itself is intrinsically CMYK, such as a laser printer, then, as described in the Wikipedia quote, many Pantone shades won't reproduce correctly. Susan did not specify whether her documents were principally for online viewing or for print, and I am afraid I sort of assumed the latter. It matters. > And what about online docs? In my (limited) experience with FM/Acrobat, > printing a Pantone colour to PDF can result in wildly out-of-whack results > (probably mangled by the Windows GDI). That is quite likely, as the Pantone system was primarily intended for physical printing onto paper, card and so on. There is also the issue of Windows itself. I have no direct experience, as I've always worked with FrameMaker on Mac (so far, at least), but I have read here and elsewhere that Windows doesn't (or did not) handle CMYK well. > Pink Pantone in FM becomes ugly orange in the PDF; blues become purples, etc. > (I realize those results may be due to my inexperience with the software; > but it doesn't sound like Susan is in any better a situation.) No, it's not due to inexperience. There are several factors at work here. First off, it's always been my experience that FrameMaker's rendition of *any* color on screen is not to be trusted: a PDF is a much better reference, and printing it even better. Secondly, you only stand a chance of seeing colors even remotely correctly on screen if you use a reference monitor, a color calibration thingie, and color profiles. I have no experience of the latter other than what I've read, as I don't take full-color work to press, only black and a spot color such as a single Pantone shade. I am unsure even whether the latest versions of FrameMaker support color profiles, but 7.2 certainly doesn't unless it's buried away somewhere and I've never noticed. >If the output is to PDF to be viewed online, then (in a Windows environment), >I find sticking to RGB is more reliable. Yes, that makes perfect sense; as RGB colors are made up from mixing three visible colors, it is intuitively likely that they will work better for a light-emitting device such as a screen, as opposed to systems such as Pantone used on paper, a light-reflective medium. But I'm just theorising here. > If the output is also/instead hardcopy produced from PDF by a print shop, > then I think you have to know more than "Pantone 72" before you can be > assured of problem-free results in both media. Sort of: if the output is a Pantone shade and the document will be printed from PDF, then if everything is working as it should (see my comment about Windows above), the color should reproduce absolutely correctly *on paper*, as that is the purpose of the Pantone system. And if not you can blame the printer. However - and it is a big 'however' - this assumes that the document has been preflighted properly and contains the correct pre-press information. This is a big subject, and one that Dov, for example, is far better qualified to comment on than me, but common errors in my own experience are spot colors coming through as process, plus extraneous color information that shouldn't be there. For example, if a document, intended for print, contains black and a spot (Pantone) shade, but the press-ready PDF specifies four (or more) plates, then clearly something has gone wrong. I spend a lot of time in the final phase of book's production weeding out this sort of thing. If a (single) document containing color is intended for both print and online viewing, then all bets are off and I guess some sort of compromise is probably required to get things looking reasonable for both, but this isn't really my area, as my documents are intended for one or the other, but not both: usually print. >Steve (and others on the list), if you have more experience and knowledge to >share, I'm sure we'd all appreciate any light you can shed! Well, I've gone on a bit above, but I should emphasize that I have only learnt enough to get me by and avoid disasters: it's a huge subject. One thing I would say though is that for documents that are to be printed by a commercial print shop, whether they contain color or not, it's essential to liaise with the print shop and if at all possible get them to specify the Distiller profile to be used. That way if things go wrong - and they sometimes do, very expensively - it's not your fault ;-) -- Steve
