Some (of my?) prepress mistakes...

[markf]

This thread kind of follows on from an earlier thread where I asked about learning about prepress issues, but some parts of the thread started to discuss some specific technical issues. So I started this thread to get down to the nitty-gritty of some mistakes I might have made last time I sent a job to a printer. The thread was here:

http://www.graphicdesignforum.com/forum/showthread.php?t=14365

Some of the quotes come from the above thread.

Here's something I said in the previous thread:

When I get the work back from the printer I'm somehow disappointed when some of the colours haven't come out the way I expected them to (for example, last time I had something which I had set to be Pantone Cyan come out as a purplish colour when I got the work back).

Here's some of the responses and some more info from me on the subject

Are you actually printing in a spot color!? If you are, then use a recent Pantone book to see your colors, not anything you see on screen. If you're not printing in a spot color, then DON'T design with one - the printer will have to convert it to process otherwise, and they might have different values for their pantones than you do. Use a Global Process Colors instead. Try to get a color guide from your printer, then do all your designs using the colors in the guide, as Global Colors.

The job was a business card, and designed the logo for the card with pantone cyan, and then tints of that cyan (it was 3 silohettes, each getting lighter). I just chose that colour from one of the pantone pallettes in Corel and it seemed to be ok. Now this job ended up being printed twice (for reasons which I'll go into in a minute). Anyway for the first time I used the joboptions file from a previous printer and I checked all the values myself. The colour on the first job was actually correct.

For the second job the printer told me to print a PDF/X-3. Ok - I'd never done it before, but the settings seemed straight forward, so I sent off the file. When the result came back the colours weren't as I expect them to be. The alignment on the card was out by 2mm - which quite a lot for a business card I thought, and what was supposed to cyan had turned into a much darker purple colour. I phoned the printer and asked what the story was, they of course denied all knowledge, then I pointed out that the first set of cards had the correct colour, and that they had an example of what it was supposed to look like (from the first print run) so why suddenly different? I always kept asking was it something I had done, if so could they tell me so I didn't do it in future? Basically phone calls weren't returned. I emailed and even posted them both versions of the cards so they could see for themselves that there was a big difference in colour. Never heard back. I resolved that I probably was to blame for the situation, hence the fact that I am here trying to educate myself. Just back to the use of spot colour - sure I realise now that this is pretty silly, but I presumed that when I output to PDF that everything was going to get converted into CMYK numbers anyways - I think I had ticked the option to do this anyway. I checked process cyan and it was 100% cyan and 0% for everything else - no problem I thought. For the first run it was no problem!

I did do some investigation into this issue later, but for the moment I should probably explain why we did two print runs. As I said earlier I produced the PDF, using the joboptions from a previous printer, and inspected the output. I checked the preflight info and made sure that all my fonts were embedded correctly. Everything in the PDF seemed to be fine.

When I got the business cards back I was shocked to see that one of the fonts had escaped from where it was supposed to be and had run out about 10mm wider than it was supposed to - it ruined the entire card. I straight away called the printer (or the printer's agent actually) and asked what the ... was the story. I should point out now that I live in Switzerland, and in Switzerland the customer is always wrong, and apologies will never be made for mistakes. Of course this was all my fault, and at first they refused to even discuss it. I tried to point out that I had sent them the PDF beforehand and asked them to check if everything was ok, and they had told me it was fine. After much diplomacy they agreed to look at it again. They admitted that when the printer tried to load it an error came up that the font was missing, so he just went ahead and substituted it, printed it, and never bothered to check if the output looked anything like it was supposed to. I sent the file again, and aparently it was the same problem. But they couldn't tell me why, or what I was doing wrong - preflight reported that all the fonts were there..

So they agreed to print again, and this time they told me to do PDF/X-3, so I did exactly what they said. As an extra precaution this time I converted all fonts to curves before I made the .PDF, because I just didn't want this to happen again. I'm guessing this is the safe option to follow, and I plan on doing it in future - unless someone tells me that this isn't the best thing to do.

Then I sent it off to print and ended up with this purple colour instead of cyan. Sometime later when I started to work on this I figured that I might have come unstuck by using a spot colour. So I checked my first PDF - yep - looked pretty cyan to me. I checked the CMYK values - yep - correct. Then I looked at the PDF/X-3 I had generated - hang on, it did look a bit purple, and the black looked more like it was grey... Very strange. There must have been some sort of colour adjustment done when I generated the PDF the second time....

So I went back to the PDF options that I had saved when I generated this file. I checked if colours were to be left unchanged - they were. But now I hunted through the advanced settings and found "Default values if not specified in the document" and "output intent profile name". This was set to "Europe ISO coated FOGRA27". Could this have messed around the with the colours? Is there something different in a PDF/X-3 that could have caused this to happen?

I guess I should have checked the file a bit more carefully before I sent it off, it's just that when the guy is telling you exactly which PDF settings to use, you kind of trust them. Then unless you see the old and new PDF file side by side, you might miss the slight colour variation.

Ned's advice doesn't apply to my end of the business where everything is done in spot or Pantone Process numbered colors and if you convert to Process CMYK colors or use that damn PMS to Process guide I will haunt your phone and email until you send me PMS numbers. (I'm serious.)

I'm not quite there yet to understand how PMS numbers might relate to what you are talking about (or indeed what PMS numbers are, or where I would find them), but I do understand that in your business the situation is different and doesn't apply to my example. But I am curious as to how and why your large format printing stuff varies. I had read somewhere that large format guys need the stuff in RGB, but I hadn't thought about why. Last weekend I had to prepare a 160cm x 60cm banner - I had about 30 minutes to do the design and email the PDF to the printing guy (different guy this time!!). I converted the images to RGB and sent them off. Afterwards I had a little think about why wouldn't I do the images in CYMK, after all this guy has some sort of big inkjet printer, and it must have CMYK inks - where did I get this idea about RGB from?? So I called him to apologise and he said no problem his print driver converts RGB to CYMK anyway. The banner looked great!

But seriously PrintDriver - i've seen that your signature warns that things are different for what you do - but I'm curious as to why this is? Can you give me a brief low down on this - or possibly point me to a post you've made somewhere else where you've already explained it?

You know, after all these years, I have NEVER trusted my monitor for color. Even after calibration. What I trust are those little numbers next to CMYK in your Info menu or in your Color menu. I get the most accurate results when I tune in to the numbers and not what I am viewing. I take eyedropper readings and I check it against a CMYK screen build reference (http://www.tintbooks.com/) or Pantone book (http://www.pantone.com./) if nescessary.

Color correction is indeed an art. Nothing will match hands on experience, but there are some very good references out there. Peachpit Press has a book called "Photoshop Color Correction" that is quite good. Digital-photography.org (http://www.digital-photography.org/learning_CDs_Adobe_Photoshop/learning_tutorial_scanning.html) has a training CD called Scanning and Color Corrections in Adobe Photoshop which is good for beginners.

This sounds like good advice. I think I'm going to go and buy these books/references. I'd also like to calibrate my monitor and will probably look at buying one of these hardware devices to do it. But then I probably should buy another monitor, so I'll do some research on this separately. Just one question - it's one thing to have a book of pantone colours if dealing with an area of solid colour - but I'm guessing this won't make a shred of difference if I have images in my work since they are composed of many different colours anyway?

Just as a side note, to the original poster - this probably won't apply to much of what any of us are doing here, but if you're desiging to print directly off your home inkjet/bubblejet printer, the file should be be in RGB. Home printers are designed to print best off RGB color models. I suppose they just figure that the average desktop user is not print savvy, and does most of his/her printing off the web. ;)

A-ha... Now I know where I got that RGB thing from... Ok now why is that? Does the print driver do the conversion? When converting from RGB to CMYK wouldn't it just be a straight mathematical conversion? Plus I presume some sort of compensation would be done for the individual device itself to boost some values and lower others. But this should have nothing to do with the values I have set in a PDF, I presume the device would do such compensation automatically?

That's it so far - thanks for your help and looking forward to your replies...

Mark

[rickself]

Hey Mark...I think it was Wednesday when I started reading your post...now it's almost Thursday! haha, just joking!


First off, I'd search for a new printer.
Second, rgb doesn't just convert to CMYK. There are a lot of combinations that CMYK cannot even come close to.
Third, in printing, you cannot assume anything.
Four, I'd search for a new printer.
If you have to use pdf, PDFx1A Has always been good and reliable for me.

Good luck, welcome!

[Vikia]

Just one question - it's one thing to have a book of pantone colours if dealing with an area of solid colour - but I'm guessing this won't make a shred of difference if I have images in my work since they are composed of many different colours anyway? Actually I should have said the Pantone CMYK swatch book which gives Pantones in cmyk readings. So yes you can match colors to Pantone if you adjust your levels to give readings close to specific Pantone cmyk formulas. I like the other non-Pantone version because it is accurate and costs a lot less than the Pantone versions.

[PrintDriver]

PMS numbers are Pantone color swatch numbers, not the CMYK values Viki is talking about.

As for large format, most will accept RGB images because they have to custom profile all the images for the specific media being printed on anyway. Some will want you to do the CMYK conversion so you will know if there are any color shifts you should deal with. Always best to ask.

-Large format doesn't use seps.
-It is very dependant on being able to crossmatch actual PMS callouts rather than CMYK build to get accurate color matches.
-Each printing machine prints color differently. A CYMK build on a Mutoh will not print the same color on a Colorspan. The inks are different, the profile is different and then you throw in the added confusion that each media (vinyl, nylon, paper, etc) has it's own profile. So a Mutoh printing on Paper will not match a Colorspan printing on vinyl right out of the box until there is some some form of serious color management going on in the printshop.That color management relies on being able to match the individual PMS color swatch from a Pantone book by number. And one more thing to add to the mix. Each vinyl product, each fabric product, each paper product has its own profile. It's a wonder it all works out sometimes to give you a beautiful banner.

Check out the Resource section. There's a post there about wide format requirements and one on banners too.

Remember that anything you might read here is always superceded by the specs of the print vendor you are using.

[cjoe]

PMS numbers are Pantone color swatch numbers, not the CMYK values Viki is talking about.

As for large format, most will accept RGB images because they have to custom profile all the images for the specific media being printed on anyway. Some will want you to do the CMYK conversion so you will know if there are any color shifts you should deal with. Always best to ask.

-Large format doesn't use seps.
-It is very dependant on being able to crossmatch actual PMS callouts rather than CMYK build to get accurate color matches.
-Each printing machine prints color differently. A CYMK build on a Mutoh will not print the same color on a Colorspan. The inks are different, the profile is different and then you throw in the added confusion that each media (vinyl, nylon, paper, etc) has it's own profile. So a Mutoh printing on Paper will not match a Colorspan printing on vinyl right out of the box until there is some some form of serious color management going on in the printshop.That color management relies on being able to match the individual PMS color swatch from a Pantone book by number. And one more thing to add to the mix. Each vinyl product, each fabric product, each paper product has its own profile. It's a wonder it all works out sometimes to give you a beautiful banner.

Check out the Resource section. There's a post there about wide format requirements and one on banners too.

Remember that anything you might read here is always superceded by the specs of the print vendor you are using.

I was just wondering, its a bit off thread, but when you are calibrating your printers, do you just print off a test sheet then match it to Pantone swatches to get correct colour?

[Ned]

The job was a business card, and designed the logo for the card with pantone cyan, and then tints of that cyan (it was 3 silohettes, each getting lighter). I just chose that colour from one of the pantone pallettes in Corel and it seemed to be okay.

I see, Mark... I thought you were desigining in spot, but not printing in spot, because spot colors are exact, and I couldn't foresee any change in the final product. However, if you picked your spot colors out of the Corel color pallete, and not a physical pantone color book, then that is where your problem is. When you use the computer's color pallete, you are relying on your monitor calibration, and a myriad of other factors to determine what color gets to your eyes, not to mention the fact that pantone does change their color formulas, and your Corel pallete may not be updated. When designing in spot colors to print in spot colors, ALWAYS use a book, not what you see on the screen.

All in all, monitors are not meant to display process colors, and paper was not meant to display light colors. CMYK and RGB gamuts are so different. RGB can display all those bright neon lights, CMYK can print all those dark muted tones. So when designing for print, you always want actual printed colors (CMYK Tint Book, Pantone Color Guide, etc.) to go by, so you can key in those exact CMYK values or Pantone colors, etc. into your program.

[markf]

Hi Ned,

Good points, except that while I was using a spot colour, I also checked the CMYK value and it was 100,0,0,0. I'm sure you'll agree that you don't need to see a pantone chart to know that this is about as cyan as you can get :), to be honest, I wouldn't have noticed if there were slightly different shades of cyan, but the problem is that after I produced a PDF/X-3 the colour values totally changed - to a purple colour! (85,36,8,7). Now the thing is this didn't happen when I produced it the first time (as a normal PDF). I removed everything to do with colour correction from the job options in Acrobat, and it still screwed it up!

I can accept that I have to check colour charts etc, but when I know I want cyan, it's rough when I can see for myself that the numerical values have changed to something which probably isn't cyan. The purple colour that ended up on the final print did closely match what the purple colour looked like on screen, and the cyan colour in the first print run also matched closely with the cyan colour in the corel file.

Still confused...

[markf]

Ok, some things are becoming clearer - some not... Ok, so I went into Corel, I looked again at my Pantone Cyan, so I decided to just convert it back to a CMYK colour in Corel, so nothing else could happen to it. So I checked it before I changed it - the CMYK was reported as 100,0,0,0 as I expected. I click on the fill colour and switch the tab from from palettes to models and select CMYK. Except now it reads 81,28,0,19... So then I manually change it to 100,0,0,0. Now the colour looks AWFUL on screen, way too light. So I print it as a PDF/X-3 - now it looks ok again - more like what I'd expect to see in print.

Since I rarely work with spot, I guess the solution is as you guys say - go buy a book with the swatch of all the CMYK values in print and work with those.

Just to be sure I loaded the PDF I produced into photoshop and checked the colour. Now it is 81,37,8,7. This is driving me nuts - seems to be different every time I do something :confused:

One day I'm going to figure all this out...

Just one question - if I get a book of CMYK values - surely there is no such thing as the perfect colour match? I mean each printer must have slightly different results depending on his printing hardware, inks used and the stock he prints on. Therefore it might be impossible to make a reference like this?

Sorry for all the stupid questions guys, must seem pretty simple to you!

[urstwile]

I'm confused here. For the business card, is it your intention to print the CMYK version of a spot color? Why? Does your printer not have the Pantone ink you specified in your design available?

Your first post was very long, so it's possible I missed some critical aspect of what your final output intention was, but in general, it's quite acceptable to design using spot color for things like business cards and letterhead, etc., since it's often much more cost effective (2/C vs. 4/C).

If, however it was your intention to print the job in process vs. spot, then yes, a CMYK tint book is the way to go. Never trust software conversions to be correct when going from spot to process. I just recently discovered that the Quark conversion from spot to process is different from the Photoshop conversion, so that's why you need to go the route of using what Pantone says the conversion should be.

[Ned]

Yes, I can certainly see where your frustration is setting in, Mark.

My best piece of advice at this time... Keep everything within the Adobe Creative Suite (Photoshop, Illustrator, and InDesign), and try to get away from Corel altogether. If you need to take something from Corel, bring it into Illy, ensure everything is as you had indended there, and then keep everything in native Adobe file formats like PSD, AI or INDD, until the very final output to PDF. PDF is an Adobe format, and Adobe has consistent color management only as long as everything is kept within Adobe format. Do your final output to PDF using any one of Adobe's programs, but preferrably InDesign or Illy, without using Distiller. Then you should be alright... I think this is just a workflow problem, not so much a technical issue. That's the only reason I could see for your color values changing as you go along.

[markf]

I'm confused here. For the business card, is it your intention to print the CMYK version of a spot color? Why? Does your printer not have the Pantone ink you specified in your design available?

Well my intention was never to use spot in the first place, it's just that the pantone palette seemed like a nicer place to go hunting for the colour I was looking for. When I found one that looked nice I figured it would all get converted to CMYK when I made my PDF anyway. For the first print run (without colours being messed around) the theory worked fine - I got exactly what I expected.

The printing product I choose was a 4/4 business card, there was no mention of the possibility to use spot, I would guess that this would fall outside of the standard options given by the printer. The amazing thing about this printer is reasonable cost. I had 1000 of these cards on 300 gram stock (satin finish) done in 2 days for the equivalent of about $80/E67. Switzerland is a high cost country and this kind of price it was very impressive. As I said earlier I saw everybody's elses output (flyers, brochures etc) when I went to collect and the quality was impressive! So just to summarise - I didn't intend to design with spot, it just kind of happened that way.

To be honest, I think I've been hit by some sort of colour correction issue, which has nothing to do with spot to CMYK conversion. I confirmed this last night by going through the exercise again without the spot colour, and I still had a lot of values changed in the final output!

Yes, I can certainly see where your frustration is setting in, Mark.

My best piece of advice at this time... Keep everything within the Adobe Creative Suite (Photoshop, Illustrator, and InDesign), and try to get away from Corel altogether. If you need to take something from Corel, bring it into Illy, ensure everything is as you had indended there, and then keep everything in native Adobe file formats like PSD, AI or INDD, until the very final output to PDF. PDF is an Adobe format, and Adobe has consistent color management only as long as everything is kept within Adobe format. Do your final output to PDF using any one of Adobe's programs, but preferrably InDesign or Illy, without using Distiller. Then you should be alright... I think this is just a workflow problem, not so much a technical issue. That's the only reason I could see for your color values changing as you go along.

Funny - this was a conclusion I was starting to come to last night myself. I've come up against the problem in the past that people only want to take Illustrator files, maybe this is not widespread, but it seems to be the case with the people I've dealt with in the last few months. Therefore I was already considering switching to Illustrator (I already use Photoshop, so only Corel is the odd man out). The problem is that I've used Corel for years, and have just bought some more books for it. Illustrator is already installed on my machine (since a couple of weeks ago), but the learning curve seems to be steep. I'll have to get some books and spend a bit of time with it - at first glance some aspects seemed to be very different than Corel.

But at least for the next month or so I have to continue with Corel for the basic stuff I have to get done. In parallel to this I think I'm going to try and buy some books on colour management and try and get to grips with the technical issues here.

Thanks for the tips!

[Ned]

If you can master Photoshop, and you've already got a firm grasp of Corel, then you can master Illustrator easily.
Basically, it's got all the same Adobe workspace, shortcuts, etc., but it follows the same concepts that other vector drawing programs like Corel do.

This is exactly why I love Adobe products... I jump between Photoshop, Illustrator, InDesign, After Effects, Premiere, and Audition without any glitches, and I'm always using industry standard programs.

[markf]

Actually I should have said the Pantone CMYK swatch book which gives Pantones in cmyk readings. So yes you can match colors to Pantone if you adjust your levels to give readings close to specific Pantone cmyk formulas. I like the other non-Pantone version because it is accurate and costs a lot less than the Pantone versions.

You said the "other non-Pantone version". Did you mean this one (http://www.amazon.com/gp/product/0811827577)? If so - that's the one I'm about to buy, please let me know if I should get something else.

If you can master Photoshop, and you've already got a firm grasp of Corel, then you can master Illustrator easily.
Basically, it's got all the same Adobe workspace, shortcuts, etc., but it follows the same concepts that other vector drawing programs like Corel do.
Well I don't know if "master" is the right word. I'm plodding through the classroom in a book series and seem to be getting most of it. That is until I sit down with a real world problem and have to think "now what was that thing with the clipping mask again?". It's fine when everything is shown step by step, but the real world is something else :-) I'm about to order the classroom in a book for Illustrator as well.

Which brings me to my next point, I've put everything I'm about to buy into a wish list which you can read here (http://www.amazon.com/gp/registry/19DV3X6LIUSSL). I'd be grateful if anyone/everyone could take a quick peek and tell me if I'm on the right track with some of those books...

[Vikia]

That one should work just fine.

[urstwile]

Not to belabor a point, but it should be acceptable to design in spot (Pantone or other) color, for certain situations. In many cases, it can be much more cost-effective, unless your printer just doesn't have spot color as an option?

In addition, the Pantone library can often offer a lot more variation in color than the regular CMYK gamut, and is perfectly acceptable for use in design of business cards and other "identity" elements. It's a totally different type of ink, so has its own issues, etc. But for identity colors, spot color is fine for use in design. Especially if you have a recent swatch book and can show your client chips of what the color looks like.

You do have to pin down the color conversions for those spot colors in CMYK for advertising in magazines, etc., but it's definitely not wrong (at least here in the U.S.) to design identity materials with spot colors, unless you want a 4/4 allowing you to use colors beyond say, two. Perhaps it's different in other countries?