June 22, 2011

The Seven Deadlier Sins of Print Streams

The response to our ‘Seven Deadly Sins’ article in the June Crawford Courier newsletter was amazing. Since publication, we have had an outpouring of additional stories about the problems caused by people who had committed these deadly sins. Our customer support people have also been hard at work coming up with additional evils committed in the industry, thus prompting this article – ‘The Seven Deadlier Sins of Print Streams’.

Whether these are deadlier sins than our original list may be up for debate, but we think you’ll agree these offenses are particularly heinous. Here they are:

1)    Always include all resources within print jobs
2)    Never provide postal information as graphic images instead of using fonts
3)    Never assume your GUI composition software or print file viewer exactly matches the print output
4)    Never include duplicate resources when concatenating files
5)    Never use subset fonts
6)    Never use white print or invisible text
7)    Never use dynamic creation, deletion and re-creation of the same font within a print job

1. Always include all resources within print jobs. 

When print resources such as fonts, images and form overlays are not embedded in print files, there are serious limitations on what can be done with those print files. The correct resources are required to be merged with the print file in order for the print files to be processed correctly. If for some reason, the incorrect resources are used when the file is printed, displayed or processed for other purposes, then the results will be unpredictable, perhaps even catastrophic.

Now, you AFP users out there might say “just a moment – AFP is based on the concept of keeping resources separate from print data.” It is true that the AFP architecture is based on centralized libraries where resources such as fonts, images and form overlays are stored for use with print files. Everything works fine when all printing and processing of the print files is done on that mainframe system. However, when the AFP print files are exported to other systems that cannot access those libraries, then all sorts of problems can occur if incorrect resources are used.

2. Never provide postal information as graphic images instead of using fonts.

If postal information, such as name and address fields, delivery point zip and postal codes are embedded in the print file as a graphic image instead of as text fields, this information cannot be extracted from the print file when needed.

What might it be extracted for? Well, as we discussed in the Seven Deadly Sins of Print Streams newsletter article, functions such as automated document assembly, mail tracking, document integrity tracking, batching, house holding and use of alternate distribution channels may be needed with the documents at some point. When that happens, having the delivery information in graphic images will make these capabilities virtually impossible.

3. Never assume your GUI composition software or print file viewer exactly matches the print output.

We have seen people who assumed that because the print stream viewer showed the desired results get burned when the print file was printed on an actual printer. After they sent the resulting printed output to the shredders and scraped the egg off their face, they realized how important it is to perform a test of their applications using the actual target printer before they declared the application fit for production usage.

4. Never include duplicate resources when concatenating files.

Many newer applications do not create print documents in large print files. Often single bills or statements are output in separate print files, which contain all the resources needed to print or display the document.

This works fine when the volumes are very small, but when there are more than a dozen of these, it will be more efficient to concatenate these print files into a single print file that can be managed more effectively. If the software used to concatenate these print files (or PDF files) allows all resources to be included in the output file, then problems are going to ensue.

Let’s say your volume grows so you are going to concatenate 100,000 print files, and each print file has 2 form overlays and 5 fonts. The resulting print file will have 500,000 fonts and 200,000 forms. No printer can handle a print file with that many resources in it. Problems are going to result doing any post processing of these print files.

Alternatively, intelligent software should be used which can detect and eliminate the duplicate fonts and forms when concatenating these print files.

5. Never use subset fonts.

Many print drivers and PDF creators have the ability to created fonts which are subsets of the entire font being used. A subset font usually only contains the characters from that font which are actually used in that document.

This approach can create a smaller output file when the document size is small, and many characters can be eliminated. However, if post-processing work such as document reengineering or print file concatenation are ever performed on the print file, it can backfire on you.

Even intelligent print file concatenation will not be able to eliminate duplicate fonts when the files are concatenated, so the number of fonts embedded in the output file may be so great that the print file is unprintable.

6. Never use white print or invisible text.

Sometimes people will place indexing or other (sometimes confidential) information in documents using a pointsize too small to create printable text or in a font that has a foreground color that is the same as the background color. This can cause a few different problems, particularly if the document is converted into a different format.

This may well happen for online viewing in HTML or PDF, or into a different print format. Often the previously invisible text shows up on the page after the conversion, due to some incompatibility ruining the documents.

Another issue that can occur is that confidential information contained in the hidden text is still in the document and may be detected and extracted causing potential privacy breaches or security exposures. It is better to use proper structures such as AFP TLE records for indexing information.

7. Never use dynamic creation, deletion and re-creation of the same font within a print job.

In some print formats, such as PCL, fonts can be embedded in a document and they can also be deleted. These operations can occur on different pages, so it is possible to embed a font on page one, delete it on page five, and then embed a different font with the same identifier on page seven. This severely limits what can be done with these documents as they are not page independent.

That says the pages must be all printed or displayed in the same sequence in order to get correct results. Sorting the pages for postal optimization will cause problems. Converting the documents into a viewable format such as PDF or HTML will most surely result in formatting errors.

If you know of any sins we have not covered yet, we invite you to submit them in the comments section below.

The original article from our recent newsletter, The Seven Deadly Sins of Print Streams, is also available...