Inkscape Circles change dimensions when exporting to PDF

Question

I have a 20 concentric circles in Inkscape, not filled, with a white semi-transparent border. Like this:

When I export it to PDF, the circles are resized and they become ellipses, revealing the background behind them:

Any idea why and how to avoid this? Here are the svg and pdf files:

• https://www.dropbox.com/s/91njrcoxjs5akg8/test.pdf
• https://www.dropbox.com/s/0t4z9hkwqb82vjz/test.svg

Answer 1

When we look at the dimensions of the circles in your SVG we can see that each of the circles in fact is not a circle but an ellipse. Also the stroke width varies from circle to circle being approximately 5 px only.

To clean this up I

• selected all objects with the select tool.
• adjusted the height and the width to exactly 340 px
• corrected the stroke width to 5 px exactly.

This led to a much better rendering of the SVG: