When embedded fonts are subsetted it ensures only those characters that are actually used in the file are embedded. If the "$" character doesn’t appear anywhere in the text, that character is not included in the font, reducing the size of the embedded font. This means that PDF files with subsetted fonts are smaller than PDF files with fully embedded fonts.
In version 9 of NXPowerLite Desktop, the PDF optimization setting ‘Subset embedded fonts’ was enabled by default. In previous versions this was disabled.
How does subsetting of embedded fonts in PDF files affect NXPowerLite compression speed?
When NXPowerLite has font subsetting enabled it has to analyze all of the text in the PDF document to determine which characters of each font are used. Once complete, it deletes each embedded font before inserting the new subset of the embedded font.
For most files, this process will add a small amount of time, but for files with a large number of pages, or using many fonts, or both, this can significantly affect the processing time. For some files, this increase of time will yield much better compression results and for others, it will not. There is no way of knowing this without trying it.
Disable the ‘Subset embedded fonts’ feature in NXPowerLite
If you think the processing is slow for some files and you don’t want NXPowerLite to subset fonts, follow these steps to create a custom Optimize profile to apply when compressing files:
- In NXPowerLite Desktop, select New optimize profile... in the Optimize profile drop-down control.
- In the PDF tab, uncheck the setting Subset embedded fonts
- Name the profile. E.g. PDF no subset
- Your new profile will be automatically selected as the current Optimize profile. Now just compress your PDF files as normal, and the fonts will not be subsetted.