If you're sending work out to a traditional printing company that uses printing presses, it should be CMYK. If you're just printing your posters on a color inkjet or laser printer you're often best just sticking to RGB.

Printing presses use cyan, magenta, yellow and black ink (CMYK) to create all the other colors. This is also called 4-color process printing. These inks are not capable of reproducing all the colors your monitor will display. When you work in CMYK, your computer will display an approximation of only those colors that cyan, magenta, yellow and black ink can print.

The very bright and vivid colors that you see on your monitor in RGB (red, green and blue) can't be reproduced in normal 4-color process printing. For that matter, those colors can't be reproduced by either an inkjet or a laser printer either. However, these desktop printers often use more than just cyan, magenta, yellow and black inks. For example a desktop printer might have a bright and not-so-bright cyan or magenta that, when combined together, will create brighter and more vivid colors than is possible with 4-color process.

If you want to do a little searching on Google, look up the difference between "additive colors" and "subtractive colors." All printed materials combine inks together in a subtractive process to create all the other colors. Your monitor or your television uses "additive colors" where light itself, instead of ink, is combined to create all the different colors.

Mix cyan, magenta, yellow and black ink together and you'll get a solid black (all the light reflecting off the printed surface is subtracted by the inks to form black). However, when you add red, green and blue light itself together, interestingly enough, you get white (all the light emitting from the display is added to create white). Understanding a little bit of the physics behind additive and subtractive colors will help you understand the conceptual differences between RGB (additive) and CMYK (subtractive) colors.

Quite a few digital large format machines have wider gamut ink sets. You could quite possibly find someone to print your posters who has a machine that has the CMYKOGV ink set.
(OGV = Orange, Green, Violet).
The thing with these is they are aqueous inkjets and would have to be laminated. All water-based inks are subject to smearing if they get the least bit wet.

Thanks again.

So now let me ask you this...


What do you guys typically tell or ask a client about printing before accepting a project?

It's not a big deal because this isn't a huge client or anything, but I already showed her some stuff with color that might not at all look the way it does now depending on the printing process, so I'm assuming everyone has some sort of code of conduct when it comes to discussing printing with clients...

Thanks.

I tell them that screens vary and that screen proof is only a very rough guide.

Every printer is slightly different and even paper stock can change the colour.

If a client is fussy about colour, I get a printed proof on correct stock for final sign off. If it's an offset job and the client has signed off on that colour, they printers are supplied with the signed off proof to match to.

If you want a printer to hit a particular colour, always supply a sample. Too many people supply a proof to match to AFTER the job has been printed incorrectly.

Using a color matching standard like Pantone helps... Trying to match colors to a teeny tiny logo printed low end on a business card isn't a lot of fun. Nor is matching a chunk of wallpaper torn from a roll. Nor various other weird and sundry objects sent for color matching.

Thanks.

So going along this same topic, I read on this forum somewhere about people talking about transparency printing.

If I were to use a soft 40 or 50% eraser in Photoshop, would this technically give the printer the same issue as transparency or does this work fine?


Thanks again for all the helpful info.

does your image have a transparent background?

I have a watercolor effect on top of a white page. The watercolor effect is the bit that's erased, so techincally I have a solid white background that everything is on top of.

Yes, in normal ink on paper printing, there is no white ink so any "white" in your file will be left unprinted or "transparent".

When you move onto specialty printing like foils, screenprints etc, you'll have to start looking at spot colours where white is printed.

So in order to achieve more subtle colors, I should just choose less vibrant colors instead of erasing any bits or any transparencies...Or is there a way I can have the color effect fade into the white of the page?


Thanks again.

What about blending modes like overlay and multiply? Does that technically count as transparency too?

The client wants an overlay effect sort of like a watermark, so I'm thinking I'll have to mess with opacity and get a proof to achieve the proper result.

Thanks.

Not quite sure what you are asking. Part of it sounds like a very basic transparency mask question. Part of it, I'm not so sure.
Can you post a picture?

Sure. I attached it to this post as a jpg.

So the blue color is all the same, Pantone Blue U.

The watermark effect I described is set to "multiply" ontop of the book. This gives it that transparent look.

The watercolor is faded into white on the page as well.


I'm thinking this SHOULD look fine, but best to do a proof on the printer and method that will be used for the final printing.

I understand transparencies aren't the greatest to work with, but the client requested this type of look exactly, and I've had transparent stuff printed before without any major problems, just a few adjustments here and there.

On a side note, I made the document 9x11.5" with .5" margins on all sides to ensure there are no bleed issues... Is this wise practice or should you typically just make the document the size it will be and factor in the bleed margins from there?

Thanks again!

PS: the colors look much more vibrant in this attachment for some reason... The saved JPG doesn't even look like that. The point is still there though.

Pantone Blue? It looks like you've got some green in there too, so unless I'm really misunderstanding things, you've got at least three spot colors in all this. I guess I'm still puzzled over why you're going about doing what you're doing.

Why aren't you just printing this CMYK? Why not just get it the way you want it, flatten it, convert it to CMYK, then bring it into InDesign to add the line art? It probably won't cost you more than three spot colors.

You mentioned CMYK not giving you vivid enough colors, and yes, it's true, you'll find Pantone colors that can't be reproduced accurately with CMYK. Once in CMYK, however, you can boost the saturation just a bit to get what you can out of the colors.

Yes, it's possible to blend spot colors and get just the right effects, but sometimes it's a pain in the butt and just not worth the effort for all the reasons that you're running into. You also can't count on spot colors blending to produce exactly the color that you think they'll make when blended. Unless you really know what you're doing, it's a gamble.

Are you possibly confusing bleeds with margins? The margin is the safety and aesthetic area you leave between the printed artwork, like your type, and the edge of the trimmed size of the final piece. The bleed, on the other hand, is the amount you extend whatever artwork, like your watercolor art, that bleeds off the edge of the paper. A bleed usually extends 1/8 inch beyond the trim size. This is to allow for the slight inaccuracies in trimming. Any printer who can't guaranteed trim accuracy to within an 1/8 inch on a letterhead is likely a printer you shouldn't use.

Again, I'm not so sure that I'm really understanding all your questions and why you're going about what you're doing the way you are.