One important aspect is which Cairo version you have installed. The newer Cairo is, the more capabilities it has in preserving transparency and filters in the PDF. In some situations Cairo is forced to rasterize in order to represent the graphic in the PDF.You have cairo 1.8.8, which is good. And you can see that it doesnt preserve transparent vectors in the EPS, while it does in PDF. It cant properly represent your semi-translucent bar stroking so it rasterizes these parts of the graphic in the EPS file.See: http://en.wikipedia.org/wiki/Transpa..._in_PostScript