Sometimes you get unexpected results when you use a PDF document as a background.
A PDF used as a background in a merge or superimpose operation is often referred to as the letterhead, watermark, logo, or briefpapier (in German). These documents can have properties that make them unsuited for this purpose. Among the common problems are font, color model, and transparency issues.
The result of using a problematic PDF is often strange colors or strange-looking text.
Normally, you can clean the PDF by printing it to a new PDF. This process can rewrite the structure of the document so that it can be used in the merge or superimpose operation.
A method that often works is to open the PDF in Adobe Reader and print it to a Bullzip PDF Printer installed in XPS mode. The method is not bulletproof but is often a good first try.
Text that looked strange before will most likely be fixed. However, you may not be able to select and copy/paste it as text anymore. Also, colors are now likely to be close to the original but there may still be small differences.
You can play around with this process to see if you can get a better result. Here are some parameters that you can test with different values.
- Try to print it from other PDF readers such as Bullzip PDF Studio or Sumatra PDF.
- DPI and color models.
- Print quality setting on the document tab.
It is often a combination of printing the PDF from a specific PDF viewer to a specific PDF printer that will remove the commands that are causing the problem.
Here are some PDF viewers to try:
- Bullzip PDF Studio
- Adobe PDF Reader
- Sumatra PDF Reader
Combine that with printing to one of these PDF printers:
- Bullzip PDF Printer
- Bullzip PDF Printer in XPS mode
- Microsoft Print to PDF
If you cannot fix the PDF yourself, then it may be an option to go back to the designer and have them try to create a PDF without transparency and special font information. It may be that they can change some settings in the PDF export that will fix the problem.
The PDF printer was originally based on converting the output from Postscript drivers to PDF. This way of doing it has served the purpose well for a long time. However, sometimes the output can convert in ways that do not serve the end purpose well.
Especially font issues have been a reason to look for alternatives to the Postscript driver technology. Postscript has built-in fonts and different strategies for embedding subsets of fonts which may not work well with software that tries to read or copy/paste the content of PDF documents.
To fix some of the Postscript related issues we have added the option to use an XPS based driver. The functionality of the XPS based approach supports fewer features but it solves some of the other issues.
You can tell the installer to add a PDF printer based on an XPS driver by adding the /XPS switch to the command line of the setup program.
The following command line is an example that shows how to add an extra PDF printer named “PDF Printer (XPS)” to your system.
Setup_BullzipPDFPrinter_11_10_0_2761_PRO_EXP.exe /XPS /PRINTERNAME="PDF Printer (XPS)"
The new printer will ask the printing application to print using an XPS based driver and convert the output to PDF.
When you merge PDF documents, you may see font information looking like this:
It tells you that the same font is included many times in the resulting PDF document. This will take up more space in you should try to avoid this.
The reason behind this behavior is that you are including a subset of a font every time you append a new PDF. If you use characters from the font that you didn’t already have in an included subset, it will include a new subset.
You can fix this by selecting to include the full font when you create the first PDF or the first time it is used. To do this, you should open the options dialog and select “All” in the Embed Fonts setting.
Keep in mind that changes through the options dialog only affects the logged in user. If you want to force a setting for all uses you should add the following lines to your global settings file.
Sometimes you can experience font problems when printing to PDF. Many different problems can cause fonts to be missing, render as boxes or look like strange unknown characters or artifacts. Usually font problems are related to specific application. Some applications may be using the Windows print system in a different way than other programs. This can cause font problems that only occurs when printing from these systems. Here are some tips on what you can try to solve the font problems.
Embedding fonts in your PDF
The PDF printer supports different levels of font embedding. When you embed a font in your document then the information about the fonts are saved with your PDF file. When fonts are not embedded then the PDF may show strange things such as small squares or nothing at all when you open the PDF. By default, the printer embeds the characters that are used from the fonts in the PDF. You can change this setting from Subset to All and hope that the extra font information solves a font problem that you may be experiencing. Font embedding is changed in the Options dialog.
TrueType Font Download Option
The second thing you can try is to change the TrueType font download option in the printer’s advanced settings. It is set to Automatic by default but changing it to outline may solve the missing fonts problem.
Normally, you can get to this dialog when you print. In the Print dialog where you select a printer there is a button named Preferences. Click that button and then click the Advanced button.
If you want to change the default behavior to outline then you should open the Advanced Options dialog from the printer properties in your list of printers. On the Advanced tab, you can set the printing defaults.