PDF Specs

PDF formatting and optimization

This page provides information regarding PDF formatting and optimization, as well as a process for creating the best black and white images for print.

PDF Creation Tips

Our site allows you to upload a complete PDF file, giving you ultimate control over the layout of your book. If you are a knowledgeable user of tools like Adobe InDesign, Photoshop, iPhoto Book Help, and other similar applications, it is critical that you understand how to create a PDF that will print exactly the way you intended.

If you are planning to upload your own PDF, you may use any fonts you like, but you _must_ embed the fonts in the PDF before uploading it. Not as a subset, but the _full_ font family _must_ be embedded.

Here are a few key tips that will help:

  1. You _must_ embed ALL fonts, which can be trickier than it seems. This is often a setting in the PDF export or distiller dialog box. This means embed the full font family, not just a subset of the font. Files created in the earlier versions of Adobe InDesign, pre-OS X, often experience missing font characters. Please use a later version of Adobe InDesign. We have seen text converted to outlines so the text is only vector art, not fonts. See our Adobe InDesign page for issues specific to Adobe InDesign.
  2. The full wrap cover and the interior (known as the text block) are printed as separate documents. It is best, though not required, for you to organize your files as two separate documents.
  3. For all books, page 1 of the text block always falls on the right, opposite the blank inside front cover. View continuous, facing pages in your PDF application to see exactly how the *inside* of your book will print.
  4. Make your PDF +.25" (+7mm) larger than your desired book size.
  5. You should have no crop marks in your PDF as our process automatically trims up to 1/4" from each edge. Speaking of trimming the edges, perfect bound books will trim 1/8" from every edge, and hardcover books will trim up to 1/4" from every edge. For this reason, we recommend you keep all important visual elements at least 3/4" (21mm) from the edges.
  6. When exporting to PDF, we highly recommend making your file compatible with Acrobat 6 (PDF 1.5). PDF 1.3 and 1.4 also work, though files with transparencies and layers may have issues with the older formats. If you upload a PDF 1.3 and the fonts or transparencies don't print properly we will _not_ reprint the book. A particular problem is that images with layers and transparencies will be placed as transparent elements into the PDF. The software for commercial printers (known as a RIP) does not handle all transparencies properly. This will result in an unsatisfactory print, even if the same PDF prints just fine on your home printer or viewing on the screen. We recommend PDF 1.5 for files with heavy layering and transparencies.
  7. We support PDFs in the RGB and CMYK color space for your interior text block, however your cover needs to be RGB and should be uploaded as a separate file.
  8. We have a list of PDF Creation Software that can convert your document to a press ready PDF.

You may want to consider downloading this free plugin for Acrobat called FontReporter, which is from PDFlib.

Note: you must have Acrobat. This plugin does not work with the Reader.

Consider Using the Book Designer

We recommend you use the Book Designer because it is easy and allows you to maintain control of the book layout. You can upload each page of your book as a separate image and choose to print each page at full bleed. In addition, if you need to make a correction to a single image, you simply correct that image and select the "order photo book" button and the book is recreated. No need for you to regenerate your PDF and re-upload.

PDF Settings

1)Always Embed fonts - if your PDF has text, Always embed the full font family. If at all possible, DO NOT SUBSET FONTS
  • If a font is multiply subsetted in a PDF, when presented to the rip, can produce garbled text. The RIP seems to try to build a single font resource for a multiply subsetted font. But since that font has multiple definitions in the PDF, the font resource that the rip builds can be at the very least garbled from being overwritten over and over again. Further, The RIP might reject the font resource entirely, and end up substituting Courier instead. This Usually produces expanded text, reflowing due to expanded kerning.
  • If a PDF file is built from multiple other PDF files, and fonts are subsetted in those individual files, then when they are combined, the final PDF file will have multiply subsetted fonts, which can produce this issue.

So, if you fully embed, and never subset, there will be one and only one font definition in your final file.

2) Optimize for Fast WebView
3) Compatibility: Recommend Acrobat 5
4) If available, Leave Colors As is {Leave Colors unchanged}
5) Image Compression: Color
  • Zip, {lossless, but might create huge files}
  • Use Jpeg High -> Low to lower filesize {Lossy, but reduces file size}
6) Image Compression: BW
  • Aways ZIP Greyscale images, do not use CCITT
7) Do not downsample images, Unless:
  • If your pages are fully rasterized, if their DPI > 300, Downsample to 300
8) Compress text and Line Art
9) Do not preserve OPI comments
  • Certain PDF Tools, such as Pitstop, have problems otherwise.
10) File Sizes should be < 700 MB's , preferably no more than 101 Mbytes.
11) Make sure Overprint is off
12) USE CMYK or RGB Colors in Paths that are below Transparencies. Spot colors that are below an images transparency might not print.

Bleeding the Document:

1) Have bleed @ 1/8th symmetric all around
2) Have Optional Marks offset 10 points
3) If you want bleed in your document all intended bleeding elements must extend beyond the document size by at least 1/4th of an inch total in both directions (1/8" on each side).

Image Files:

1) Do not change the colorspace of an image file, ie… if your original image file is in RGB, DO NOT CONVERT it to CMYK.
2) Do not use images with CCITT compression.
3) Do not use images with LZW compression, if at all possible.
4) Images that are Multi-Strip can print with lines between the strips. LZW is one image compression that can produce Multi-Strip Image files, especially on TIFF images. Do not use images that are Multi-Strip, but are continuous.
5) Do not use "Artificial" Greyscale, ie… RGB or CMYK images with near matching channel values. If an image is meant to be Grey, its color space should be gray.
6) The DocuSP is optimized to best print GreyScale images whose "Gamma" is between 2.2 and 2.4. If your greyscale images have a Gamma of 1.8, they will print too dark.
7) Image DPI, in its final document dimensions, should not exceed 600 dpi, and preferably should be about 300 DPI, to optimize RIP speed.

For PDFLib Users:

JPEG Files: - If a PDF file fails to RIP, and the error message is that this was due to an invalid JPEG Marker, and this is NOT due to a corrupt image {Adobe Acrobat usually pops up a message if an image on a page is indeed corrupt} then it is recommended that you use the "passthrough false" option when you are performing a load_image command.

PDFLib recommends you contact support when such an issue occurs, and provide the image that requires this "passthrough false" option, so that they can develop against this new jpeg flavor in future releases.

NOTE: CMYK, as placed by an iGen, from the Upper Surface to the lower Sheet of a printed document, ARE: MYCK. M, being on top, will be most noticeable.


How can I make my own PDF?

There are several common ways to make a PDF.
  1. Adobe Acrobat and Acrobat Professional are software packages with several tools for making PDFs from within applications.
  2. Some applications like Adobe Photoshop, WordPerfect or OpenOffice can save a file directly to a PDF format.
  3. A variety of vendors make PDF creation tools that act like printer drivers. You print to a postscript file that then is converted into a PDF. Nearly all of these tools use a version of the free program "ghostscript" to convert the postscript to PDF.
  4. It is possible to use a free postscript printer driver to make a postscript file into a PDF. This can have some of the advantages of using Acrobat without the cost.

You may want to consider using Adobe's free PDF creator software. Adobe allows you to create 5 free PDFs so you really want the file to be in its final form before you use one of the 5 conversions. Here is a link to Adobe's PDF creation software

Is there a way I can ensure that my PDF file will print correctly?

  • If your book has text, always embed the full font family for all fonts used within the document. Subsetted fonts over multiple pages can cause problems when your PDF is rasterized for print. The result can be your document being printed with symbols instead of fonts, garbled text, or missing text altogether.
  • Set compatibility mode to Acrobat 5
  • The colorspace of the PDF should be left in its original profile (Do not convert CMYK to RGB or vice-versa)
  • Overprint and Simulate Overprint should be turned off.
  • The size of your PDF should not exceed 700MB.
  • Do not downsample your images unless the images are fully rasterized. If fully rasterized and the DPI is greater than 300, downsample to 300.
  • Your final PDF should be one layer.

What should I do to set my image file settings within the PDF:

  • Image compression should be set to ZIP if you want lossless (no artifacts/distortion-free) images. To reduce file size, JPEG -> High should be used.
  • If you are printing a color book that has black and white images within it, the black and white images should have the colorspace set to greyscale. Artificial greyscale (RGB or CMYK with near-matching channel values) can be printed with cyan or magenta hues within the image.
  • Similar to the PDF settings, images should be left their original profile (do not convert from CMYK to RGB or vice versa).
  • For greyscale images, use ZIP encoding. Do not use CCITT.
  • The gamma of a greyscale image should be between 2.2 and 2.4
  • The image DPI should be between 300 and 600 DPI (300 for smaller filesize)
  • Do not use CCITT or LZW compression. LZW compression creates images which are multi-strip, and the printed result may have white lines between the strips of the image.

Are there special settings for Quick Printing vs Premium printing?

No, the general settings should be the same for either:
  • DPI settings should be 300.
  • Use an untagged CMYK workflow with CMYK TIFF's whenever possible (If the original workflow was RGB, do not convert to CMYK).
  • Solid blacks will print solid at 100% with no other colors added. If you do add colors to improve the richness of the black , TAC (total area coverage) should never exceed 270%.
  • Avoid very light color builds of less than 15%. Below 15% tint variation is very difficult to control on a consistent basis.