I was having a problem with Matlab fonts for quite a while and wasn't able to find a solution on the Internet. I eventually managed to solve the problem on my own, so I'm posting the problem and solution here in the hopes that it will help others.
I'm using Matlab R2012a and Inkscape 0.48.2 on Mac OS X 10.7 Lion. I make figures for scientific journal publications by exporting PDFs from Matlab and importing them into Inkscape for finer control over layout, etc. I like using the Times New Roman font in Matlab, so I usually use it in my figures by executing the following Matlab command after I make the figure:
set(findall(gca, '-Property', 'FontName'), 'FontName', 'Times New Roman');
I save to PDF via the Matlab command:
print -dpdf ~/path/to/file.pdf
When I then import the PDF file into Inkscape via File -> Import, the font is not rendered correctly; it's called "Times" (not Times New Roman) and it appears as a mis-kerned Arial. I do have a font named "Times" installed (as well as a different font named "Times New Roman"), which comes with the Mac. I can see the Times font via OS X's Font Book, but Inkscape doesn't appear able to render it correctly, possibly because Times is a "dfont" file.
The solution is to extract the TTF fonts from Times.dfont via the program "fondu" (available via macports) and put them in the ~/.fonts folder. This can be done in the terminal as follows:
# First install fondu via macports (www.macports.org)
sudo port install fondu
# Then extract and install the Times font in ~/.fonts
cp /System/Library/Fonts/Times.dfont .
cp *.ttf ~/.fonts
rm -rf ~/Desktop/times
Then, when restarting Inkscape and XQuartz, the Times font will render correctly when importing the Matlab PDF into Inkscape.