Chrome's PDF rendering engine seems to have a problem with clipping. The problem might be more general than that: this is a simplified version of a problem found in the wild. Mac OS X Yosemite 10.10.3; Chrome version 42.0.2311.152 (64-bit). The PostScript file at http://www.jdawiseman.com/papers/bugs/20150518_chrome_pdf_clip_stroke_bug.ps was distilled with Adobe Distiller XI Pro 11.0.11 to make http://www.jdawiseman.com/papers/bugs/20150518_chrome_pdf_clip_stroke_bug.pdf This renders perfectly using Mac Preview 8.0 (859.21), the screen snapshot being at http://www.jdawiseman.com/papers/bugs/20150518_chrome_pdf_clip_stroke_bug_preview.png But in Chrome Chrome version 42.0.2311.152 (64-bit) it looks wrong. http://www.jdawiseman.com/papers/bugs/20150518_chrome_pdf_clip_stroke_bug_chrome.png Observe, for example, the letter 'e'. In Preview its border is of even thickness, but not in Chrome. This is typical of the examples seen 'in the wild'. Not knowing the innards of Chrome's PDF rendering engine, I can only guess at the cause. But perhaps the clipping path and the stroking path have been moved relative to each other. Perhaps one of them is not changed, and in the other the position of all control points is rounded to the nearest point or something. Perhaps. This comment is at http://www.jdawiseman.com/papers/bugs/20150518_chrome_pdf_clip_stroke_bug.txt