Thank you for your post, and I apologize for the late reply.
I don't have the font "OCR B", so I cannot test. Does this issue only occur with the OCR B font? That is, if you change the field to Arial, does the issue still occur? Do you use this font with other applications? If so, can you set your printer to minimal margins and see if the error occurs?
If you have updated to FileMaker Pro 13, does the issue still occur?
Do you have issues with any other font?
Any other information you can provide may be helpful in determining the cause.
Sounds like a known issue.
For More Information see: FM 12 preview mode issue
This is one of many acknowledged bugs that can be found in the Known Bug List thread here in the Report an Issue section of the forum.
It can also be downloaded as a database file from: https://www.dropbox.com/s/jt09b82i0xijbu3/FMP%20Bugs.zip
Thank you for the link. Sadly (for me), I was the one that reported the issue on that link.
I don't see any mention in the Testing/Development notes in regards to FileMaker Pro 13, so I would need Benjamin Fehr (the original poster) to try this out to see if the issue still exists.
Yes, and I am very grateful to any folks (such as Fred) that take the time to check old bugs against Filemaker 13 and report back whether or not the bug persists in the latest version. I've been able to "close" a number of older bugs due to such reports in just the few days since release already.
Preview as well as browse mode in FileMaker 12 are never 100 percent WYSIWYG. The font will expand or contract depending on the zoom level. If you increase the zoom level to 150 percent the entire character string might be visible onscreen. This issue even appears when a font like Verdana is used.