@theozh thanks for your suggestion. I already considered this behaviour was due to the size; last time I used the extrude function, the image was about 1 m x 0,5m …. (a plexiglass signboard) and everything worked as expected. This time I started working from an A4 size, and truly speaking the functi...

Hi. I got back with this thread with version 0.92, and I'm having some TROUBLE with the Path->EXTRUDE command. If I convert the text to path and try to extrude some path of letters [ ctrl+) ], the path gets DEFORMED.... Any idea why it is happening ? SVG Image link https://drive.google.com/open?id=0...

Hi Lazur, thanks for your hint ! Unfortunately I believe that the radius propriety doesn't solve the problem to set an exact offset radius in millimeter . As a test (i.e. that we cannot set how many mm to offset the second layer) we can check these: ⋅  the extrude [ctrl-) ] settings in doc...

thanks tyler for your help !! It seems that this tecnique is something specifically made for shrinking/enlarging (inset/outset) http://inkscape.org/doc/advanced/tutorial-advanced..html