CMY data in PDF for JPEGs [do have workaround, but just)

[Steve Rickaby]

At 02:55 -0600 13/12/13, Davis, David wrote:

>Not wanting to be contrary here, but why does the PDF have to be only grayscale, just because it's going to be printed in black and white? Surely the printer driver should be perfectly capable of making intelligent decisions about converting the colours to grey.

Apparently not - I've tried it.

>(And, indeed, it will make better decisions than you can earlier in the chain, cos it will know more about the output device).

Actually, for all the book's I've sent to press, I've known more or less nothing about the output device(S) - I just get a pre-press spec from the printers, which often takes the form of a Distiller jobspec file. However, I do know a range of things that must not be in the pre-press file, such as hairlines. And color ;-)

>I mean, for instance, any domestic or office printer in existence will happily print in greyscale if you feed it a colour file (there's usually a checkbox somewhere in the print dialog). I'm sure most of us do and see this every day.  I appreciate some things look better than others when neutered like this (some hues of colour won't give very good contrast against each other in grey) ... but the remedy for that is more in choosing the colours in the first place, not in some fancy 'conversion to greyscale' process. For instance I can't think that green text on an orange background is ever going to be very clear in greyscale, no matter what point in the chain you convert it.

Well I'm not going to argue with you, but I have a pre-press spec to work to, and it disallowed C, M and Y channel data.

-- 
Steve