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I am supposed to take printouts of a few of my assignments which I had submitted digitally. I created those PDFs using (Lua)LaTeX. I don't understand the technicalities of printing much, but I have had a not-so-great experience with the printers around me in the recent past. They always ask for a Corel Draw file. I don't (and don't want to) use Corel draw. After insisting on PDFs, they told me to embed all the fonts and convert the shapes to curves (again, I don't know what this means technically, but I tried doing this). I found a way to do this which was to convert the PDFs to PS files and then converting the PS files back to PDFs (with some options). These converted PDFs were supposedly good for printing. I used the following commands on my GNU Linux machine for the conversion:

pdf2ps my-digital-pdf.pdf
ps2pdf14 -dPDFSETTINGS=/prepress my-digital-pdf.ps my-print-pdf.pdf

The printer was happy, I got a good printout so I didn't pay much attention to this issue back then, but now I want to adhere to the "best practices". So I am curious to know what precautions should one take. What are the ways for making PDFs printable? I don't want to use proprietary software, so would love to know some free software tools (preferably command line) for this.

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    There is really no reason to turn the pdf to ps qnd then back to pdf ghostscript can do all of this in one step.
    – joojaa
    Dec 6, 2023 at 10:52
  • I agree with joojaa, also the software used to create a PDF is irrelevant. Corel Draw is not the industry standard software anyway, and printers should not be asking for native Corel Draw files either, also you don't need to convert text to paths (or curves). None of what they are asking you for is standard. Also LaTex questions are better asked on Tex Stack Exchange.
    – Billy Kerr
    Dec 6, 2023 at 11:17
  • @BillyKerr Thanks for your response. This isn't supposed to be a LaTeX question. I just want to know the best practices while giving a digital file for print. Do you think a digital file is good to print as it is? (Assuming I have already taken care of margins and colors)
    – Niranjan
    Dec 6, 2023 at 11:28
  • @joojaa ghostscript can do all of this as in converting to paths, you mean? But Billy thinks that too is unnecessary
    – Niranjan
    Dec 6, 2023 at 11:29
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    The printers you’ve been dealing with have no idea what they’re doing; avoid them. PDF is meant to be portable and directly usable for printing. Corel Draw is not. @Billy It’s not a LaTeX question. The problem is not outputting PDFs from LaTeX, but the bad, misleading advice from the printer that made Niranjan think (almost certainly incorrectly) that their PDFs output from LaTeX aren’t suitable for printing. Dec 6, 2023 at 22:30

5 Answers 5

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Far from being exhaustive, just off the top of my head, the most important items:

First of all, any printer that asks for a specific program to be used should be avoided. Corel Draw is an excellent application, no problems about it at all but it's up to you what you decide to use, no business of the printer. Today, a printer needs a properly produced, press quality PDF and nothing else. If they insist on anything else, move on.

You have to make sure you understand the concepts of paper size, trim size, bleed and prepare the PDF accordingly. Anything—image, colored area, whatever—that reaches the edge of the paper has to bleed to the outside and the PDF has to be prepared with this in mind. A related issue are crop marks, some printers would also require this.

You cannot decide on color without consultation with the printer. If they have no specific processes in place, again, avoid them. In the past, we always needed to prepare CMYK material (this requires deeper knowledge and don't expect a consumer grade monitor to deliver perfect results). Today, any half decent printer has to be able to accept RGB PDFs and do the color separation themselves, without any issues, especially as the necessary settings are deeply linked to the printing process they use, the paper they use and many other factors out of your reach. You probably don't plan to produce a full-color printed magazine for a start but if color reproduction quality is really important, this goes far beyond the scope of what pieces of information you can collect from strangers on the net. You'll need gear of appropriate quality, calibrated monitors, appropriate graphics and typesetting software and years of hands-on experience with many failures behind you...

Many additional items about how to make sure you set up black and smaller sized text correctly come from that CMYK era and should no longer be important if the printer can handle RGB material correctly—their software should process it automatically and correctly. But, certainly, if you have printers insisting on old rules, they probably still use old and outdated systems. In these cases, observing old rules like making sure black text only appears in the black of CMYK, adding up to 20% cyan to larger, uniform black areas and avoiding black in RGB might still apply.

Fonts have to be embedded, that is, present in the PDF. Converting to curves is an old trick, absolutely unnecessary today. It makes the PDF larger and tends to reduce the quality of printed text somewhat by losing some of the important information (although the problem is less pronounced than back in the day of 300-600 dpi laser printers). Printers might want to stick to old habits but this only shows their incompetence. Actual errors have to be caught when they inspect your PDF for compliance and not when something doesn't print as expected. If they do no compliance checks in the first place, that's another reason to avoid them.

Images have to be of sufficient quality. This is a real can of worms. Inexperienced people will start to speak about DPI immediately but this is misunderstood more often than not. Required resolution depends on the printing process and the actual transformations applied to the image in the typeset material. So the important part is not to have a predetermined quality of input but to make sure that the output still has enough information for the images to appear sharp and full of required details (this leads to the actual pixel size of the images being important rather than DPI values, especially that the latter can be modified without actually changing the number of pixels, so being often irrelevant—even a 2400 dpi image won't do much good if it's only 100 pixels wide).

Also, PDF can use different compressing techniques for different image content and you have to chose according to the characteristics of the material: a real-life photo requires different resolution and compression settings than, say, a facsimile reproduction of black-and-white material (many people tend to use JPG for everything which is a huge error).

The various PDF/X iterations were designed to solve these issues. Software that promises to produce compliant PDFs will enumerate all these issues and many more, and warn you if something is missing or incorrectly set. Also, there are prepress tools that can check existing PDFs for compliance. They tend to be expensive, though.

Update:

Some specifics then:

  • Try to make as much of your illustrations vector art as possible. Graphs, diagrams, anything that's not a real life photo image, everything that you generate yourself and don't simply take a photo of. These give sharp lines, edges, consistent colors (colors in the broadest sense, this also applies if the illustrations are grayscale).

  • If you need to reproduce scanned, printed material, black-and-white, make sure you scan to a higher resolution (600 dpi), real monochrome (not grayscale but real black-and-white) and never save to JPG. JPG is a lossy compression and what you lose, you'll never get back, even if you resave later into a different format. Actually, except for real life pictures of people, landscapes, puppies or kittens, it's best never to use JPG to store your images in.

  • When you prepare your PDF, first try to only use ZIP compression for all images, turn downsampling off. Unless the resulting PDF is unbearably large, you can leave it like so. If you really need to have smaller files, use JPG with a high quality setting for color and grayscale, CCITT for monochrome.

  • Convert to curves using GhostScript, that's commonly available on Linux and also can be downloaded for many other platforms, and is command line. The two important switches are -dNoOutputFonts -sDEVICE=pdfwrite. You can check this with any simple PDF reader in the end, it will not list any fonts embedded, still all the letters will be there.

  • Try to avoid colored or gray (not fully black) text, especially at smaller sizes.

  • For the rest, I don't have any experience in TEX. Some quick googling seems to suggest that you can use a package named xcolor in CMYK mode and define your own colors (eg. https://tex.my/2010/02/18/cmyk-output-for-printing-prepress/, although it's quite old, things might have changed since then). But basically, probably, that's more or less the answer, you would need to define your colors in CMYK rather than RGB and hope that the PDF generation preserves them all right.

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  • Thanks for the very detailed answer. I was expecting tips like these. So I talked to the best known print shop of the town. They insisted on CMYK+shapes>path conversion, which I guess means they aren't using the modern technology... sob. I will try to check with more options. I forgot to mention something important. Most of my documents are text-based. They don't contain images. There are a few graphs here and there, but they are too produced with TeX program. So no "insertion" of image. My document will be absolutely fine without colors. In this particular case what do you suggest?
    – Niranjan
    Dec 7, 2023 at 14:59
  • I add them as update.
    – Gábor
    Dec 7, 2023 at 16:31
  • Thanks, I read all your suggestions. I will definitely work on these lines. I have already tried xcolor with CMYK, but one small problem that I am yet to solve is that I am not able to verify if my document is CMYK or RGB. Somebody told me Adobe tools tell you what model of color is used, but all the GNU+Linux PDF viewers I have so far tried fail with respect to this. How to be 100% sure that the color model chosen is correct? Also, thanks for the GhostScript parameters, I will be careful.
    – Niranjan
    Dec 7, 2023 at 16:40
  • Simply use any text editor or text viewer on the PDF and check whether you have the string DeviceRGB inside.
    – Gábor
    Dec 7, 2023 at 17:08
  • Okay, with the method I have used there seems to be no instances of DeviceRGB. There is one instance of LRGB though. Do you know what it means?
    – Niranjan
    Dec 7, 2023 at 17:17
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PDF is perfectly suitable for exchange. The format is self-contained, so the necessary fonts are automatically embedded. That being said, there’s still tons of things that can go wrong. (Page size and bleed, color space conversions, low res images, …).

PDF/x4 is a PDF substandard that aims to avoid ambiguities when exchanging with a print shop.

If you want to be professional, then provide your printer with a PDF that adheres to PDF/x4 rules.

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  • Thanks, you mentioned color space conversions. Where can I read about these?
    – Niranjan
    Dec 6, 2023 at 12:57
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    In general where can I read about the most common issues while giving something to print?
    – Niranjan
    Dec 6, 2023 at 12:58
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    The typical mistake is when text or fine black illustrations are defined RGB, and end up being printed in 4 color “rich black” instead of pure solid K. Dec 6, 2023 at 13:03
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    "the necessary fonts are automatically embedded" this is mostly true but depends on configuring the software making the PDF to embed them; the font licenses; and whether the software making the PDF honors the license if the license disallows embedding.
    – Yorik
    Dec 6, 2023 at 16:32
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    "so the necessary fonts are automatically embedded." -- They are not. They are if you do it correctly but not all do.
    – Gábor
    Dec 6, 2023 at 20:40
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I am a daily user of Corel Draw. But asking for a Corel Draw File for printing is dumb.

The standard for print is a PDF file. There is no other "industry standard".

There are programs more popular than Corel Draw, like Illustrator or Indesign. They are most widely used, but they are not standard to print.

So let me explain a bit about your options when exporting a file to a PDF.


1. Color mode

You have several color modes to use, and these depend on the print system you are using.

a. CMYK, If your print is going to a mass print production, like shefted offset, for example when you need at least 1000 copies of your product.

It also can be used in some digital large-format inkjet prints.

There is another thing to consider when using CMYK. You need to define the color profile.

A color profile dictates how much ink will be used. An example is that newspaper paper sucks and absorbs a lot of ink. So the print can easily go very dark. A profile determines then to use less ink.

The color profile needs to be determined by the designer based on the budget assigned to the publication for example.

b. RGB This is mostly used on digital prints, "office quality prints", photos, and posters.

c. Grayscale Also for large production prints, but when you are only printing a black and white product.

d. Native This is also for large production prints, but when you use spot inks. These are inks of specific colors. Imagine the box of Domino's Pizza, where you use a tone of red and blue.

2. Resampling and Compression

This is how raster images inside your document will be handled to save file size.

e. Resolution. Normally you use a maximum of 300PPI, so if one image is larger than that, you can opt to resample it. For online documents, you can lower these numbers to let's say 100PPI or less.

f. Compression.

There are two basic types of compression. Zip is a lossless method. It produces larger files but maximizes the fidelity of the images. In a professional printing environment, you do not worry about file size.

JPG for preview files or online documents.

3. Fonts

For short documents, like a poster or a flyer, you can choose to convert the fonts to curves, so they are not text anymore. This totally fixes the shape of the text in place and form.

For larger documents, like a report or a book, you can embed the fonts inside the document, so the font used is inside the document itself.

Some fonts do not allow them to be embedded, so you require the provider to have a license for the font. But this is not, either recommended or common because it can produce changes in the text.

4. Bleeds and other marks

This depends on how the document was designed. Sometimes the master file differentiates between the final size and the size with the bleeds. Sometimes you do not even need bleeds.

5. PDF version

As other users have already commented. Some versions that use an X on the name limit the features that can be included in the file, for example, transparencies or blend modes, to make a file suitable to be printed without surprises.


6. Output file vs Production file

A PDF is an output file. A file to be delivered.

The reason to never send a production file, source file, or "design" file, the native file your application uses, like a Latex file, a Corel Draw, or an Illustrator file, is that they are meant to be edited, therefore there can be unauthorized changes. For example, the fonts need to be installed on the other computer.

The other reason is your case. The Corel Draw file simply does not exist.


But there might be a valid case to ask for the source file:

You delivered a PDF file sooooo misconfigured, that they want to do it by themselves.

But asking for a nonexisting Corel Draw file is as I said, dumb.


Sometimes an alternative file to be printed is a flattened raster file. Like a JPG or a TIF file. But this is ONLY for specific cases, like large format printing, where the billboard will be seen far away, or when you have a photograph with no text.

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  • Thanks a lot for the detailed answer. I will keep these things in mind.
    – Niranjan
    Dec 7, 2023 at 15:59
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You can produce PDF/X-4 files using LaTeX. There is a the pdfx package to do that. For a start, just add

\usepackage[x-4]{pdfx}

to your document.

Before printing, you should ask the printer what format and color intent exactly they want and then configure the package accordingly.

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  • Thanks, I have tried pdfx, but unfortunately my print shop doesn't accept x-4 format PDF.
    – Niranjan
    Dec 7, 2023 at 16:12
  • @Niranjan pdfx can also generate x-1a and x-3 documents. If your print shop doesn't take any of them, it's not a good shop and you should find another!
    – Josef
    Dec 11, 2023 at 10:35
  • Unfortunately most of the shops I visited in the town demand basic PDF with CMYK color model and shapes converted to paths. I have managed to achieve this much, do you see any obvious downfall which this has and which is not seen in x-* PDFs?
    – Niranjan
    Dec 11, 2023 at 13:20
  • So they would take a PDF that's not valid x-4 but not a x-4 PDF? Seems like they have no idea what they are talking about. x-4 is just a restriction of PDF features. Every PDF/X-4 file is a "basic PDF" just with some features forbidden and some required… But for mostly text it doesn't matter the slightest anyways.
    – Josef
    Dec 11, 2023 at 16:32
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For the last part of your question, if you would like to use a decent Linux-compatible typesetting software which is capable of all of these, and is open source and free then have a look at Scribus (https://www.scribus.net/).
It is not a command-line software though.
There are several free online (video) tutorials to learn working with it from basics to advanced. It is also available for Mac and Windows.

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  • LaTeX already is a decent Linux-compatible typesetting software!
    – Josef
    Dec 7, 2023 at 12:11
  • Sure, I will check out Scribus, but AFAIK Scribus uses LaTeX backend. I don't think anything possible in Scribus would be impossible in LaTeX then.
    – Niranjan
    Dec 7, 2023 at 16:00

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