White Lines in Your PDF? Don’t Worry, They Won’t Print.

One of the most common questions we hear in the PrePress Department concerns those pesky “white lines” that are visible on screen in pdf files. The bottom line on the lines is:

  • they are a display-only apparition – called “stitching”, they will not print
  • you can make adjustments to your display in Acrobat to remove them
White Lines PDF
Transparency used in the drop shadow creates “stitching” visible when flattened for PDF/x-1a.

The Long Answer: Complex Issues of Transparency

Transparency has been available in page layout programs for quite some time now. The problems arise when you realize that PostScript – the language that is used by imaging devices for offset printing and many desktop printers – does not understand transparency AT ALL. At some point in the process from desktop to plate, transparency must be “flattened”. This can be a very complex, though behind-the-scenes, process whereby all your content containing transparency that was created in PhotoShop, Illustrator, and a page layout program is transformed into “PostScript-legal” content that can be read and correctly imaged by a RIP, yet still “looks” transparent. You may not know any of this is occurring, but it must happen in order to print.

The PDF solution

If your file is not for print (and you are not concerned about file size), there is no reason to ever flatten the transparency – the white lines will not plague you. PDF files since version 5.0 can contain “live” transparency – as Adobe realized pdf files can be optimized for uses other than printing. If your files are destined for print, however, you need to create PDF/x-1a files. These are optimized for Acrobat 4.0, and for PostScript output. Now, this is where the dreaded “white lines” issue arises. The process of flattening to create this file “cuts up” your page content into pieces or atomic regions, and these appear to have tiny white gaps between them. THERE IS NO GAP! The “pieces” fit perfectly together. (In fact, you could probably never print any lines that fine on an offset press anyway due to dot gain.)

White Lines PDF Prefrences
Adjust Preferences to hide “Stitching” lines.

The Visual Fix

Now – if print is not your issue, but you simply want to view the pdf WITHOUT the white lines showing, go to your Acrobat Preferences, and in the Page Display Tab UNCLICK “Smooth Line Art” and “Smooth Images”. By doing this, you will create another problem — if you had turned any of your text to outlines, that will now display poorly and pixellated. Again, it will NOT print that way. These are just unfortunate side effects of bridging the gap between software that handles transparency and PostScript imaging language that does not.

You will find plenty of insight in the Adobe forums from users just like yourself who were left wondering “How do I get rid of these stupid white lines?!”

ImageSmith knows the pitfalls and common stumbling blocks when moving from desktop to offset – call us at 828.684.4512 for smooth guidance on your next print project.

Creative Suite 5.5 Debuts

For the first time in years, Adobe has released an upgrade to Creative Suite “between versions”… version 5.5. In looking over the reviews and information from both Adobe and unconnected sources, it appears that the developments have been in response to the rapid proliferation of change in the world of mobile devices, apps, HTML5, CSS3 and ePUBs.

As you may know, Creative Suite comes in 5 different “flavors”, each specialized with a specific focus. This release contains a new 5.5 version of each. At ImageSmith in the PrePress department, we rely on Creative Suite Design Premium, tuned for print content as well as web design, e-books and other digital content. However the other flavors may be more perfectly suited for your line of work and creative output: Design Standard: excellent for print production, typography, image manipulation and eBooks; Web Premium: for websites, mobile apps and tablets; Production Premium: focusing on video production; and Master Collection: the best of all for “delivery of design across media.”

From what I can read online, the improvements and changes deal specifically with HTML5, CSS3, and affect mostly the production of eBooks and web content. For example, jQuery and PhoneGap are now supported – frameworks widely used in the mobile phone app development world. You can read a nice review of the changes at Bob Levine’s InDesign blog.

For the first time, Adobe now offers a SUBSCRIPTION method of payment for its software – apparently in an attempt to entice users who have been scared off by the high pricetag of the Creative Suite and its individual programs. You can still purchase as in the past or pay for the programs in a monthly fee. For an article about this see Dave Girard’s post at ARS TECHNICA.

Word is that the new CS6 will be released in 2012. You can follow up to the minute details and read questions and answers about Creative Suite by clicking this link for their Twitter timeline.