Comment 7 for bug 171631

See also the description of the 'Gaussian blur' filter primitive in the manual:
<http://tavmjong.free.fr/INKSCAPE/MANUAL/html/Filters-Pixel.html#Filters-GaussianBlur>

«Tip: Blurs created through the Fill and Stroke dialog depend on the size of the blurred object. To get the exact same amount of blur on different size objects, you can either use the Edit → icon Paste Style (Shift+Ctrl+V) command (if all the attributes are to be the same) or use the Filter Effects dialog to set the blur radius (standard deviation) to the same values. »