1 – CMYK vs RGB
2- JPG delivery

I owned the second Adobe RIP so that makes me old not smart. But, this issue of CMYK is “best” is a half truth. Here is why… I agree that ultimately the page is printing as CMYK and I agree that RGB does not look the same as CMYK but converting digital photos in RGB to CMYK using some Adobe template for some generic press and some generic printer is not right either.

Printers that take files and know their presses and know their printing habits are experts at converting RGB to CMYK. This conversion is not GENERIC.

Using Adobe view in CMYK is fine and a good way for a designer to see the final result but there is not great way to see what a page will look like until you are on press. Digital Proofs as we used to have with Scitex were pretty good but they are long gone. Most are using Epson ink jets for proofing as their is no film either.

2- JPG vs “High Res”
I had to fight this battle in the early 90′s. We did a test. 20 very high quality photos were scanned on a Hell Scanner. They were in CMYK. We made films and Matchprint proofs for each. Then we opened and re-saved each 5-20 times and printed them again. (Quality factor of 9.)

Of a group of color experts, they could not reliably pick the JPEG images from the non-compressed pages.

This JPEG myth has been around a long time. I sincerely doubt that many people went to this trouble to prove or disprove this. It is far easier to just pass it on like you have done.

Here is why this is true. DOTS, Ink on Paper — They are not perfect. The microscopic degradation of pixels from compression is mostly apparent in computer created gradations. We used to look at negatives with horror. “Gradations looked really bad.” But after we proofed them the bands could hardly be seen. But they were there. So adding a few (2-3) pixels of noise solved that problem too.

Photos are fine in JPEG just watch out for large areas of white or Seamless backgrounds. Adding just a little noise to those areas will fix that. But if the photo has the correct density of minimum dots then it will work fine too.

Hope you don’t mind the comment. Love your work!

1/ black coverage, first, know on what type of press your job will be printed on (Web, offset or digital).
For Sheet fed offset: Always use undercolor values to give large areas of black a nice and deep looking black like: Cyan 30%, Magenta 30%, Yellow 30% and black 100% instead of using only 100% black.
For Digital printing: 100% black only is sufficient as toner does not need under color values (adding CMY will actually make your black look muddy…)
For cold set web presses (newspaper): 100% black only is better and safer.

2/ Transparencies and overprints, always Flatten your artwork before submitting to your printer to avoid unexpected results and color issues.
Desktop publishing softwares offer a “Flattener Preview”, use that tool to ensure correct output of your artwork.

3/ Paper stock to be used (coated or uncoated): Uncoated paper fiber “sucks” more ink and need much more time to dry than coated paper, understanding ink values and coverage are important, also, coated paper offers a better resolution and more details for fine artwork, thin fonts and strokes will appear different depending on background coverage and registration…

Feel free to contact me if you have any questions, I’ll be happy to help.
Eric
PrintGreenUSA.com

ONE: I was in newspaper for several years, then moved on to direct marketing where part of my responsibilities were to preflight pieces designed out of house. This post is a dead-on top 10. The one other program not mentioned in no. 9 is Microsoft Publisher. I hate that program with a passion. Sure, its great for Uncle Charlie’s homemade birthday cards or Grandmas recipes, but for commercial printing it results in a big pile of crap. Can anyone say “Pocket Pal”? Publisher can’t export pdf files and when it exports jpegs, it defaults to 150 dpi. That’s bad news for any printer.

TWO: it could be helpful to educate new designers on the different types of presses and how they handle different stocks. Web presses for example, are what most newspapers use and it makes registration an art all its own. (Web presses are fed paper stock on one continuous roll and not individually sheet fed, like the offset press.)