Is there some tool or extensions to make cloud lines? I do need them to mark things in technical drawings. The lines in the svg where made with some other software and imported into inkscape just to show what I am after.

cheers bernd

Easily done. 

Here's my first ever Inkscape tutorial.  I'm not sure how much detail to use here so please let me know if you can follow this.  

The attachment lost all my text!  My local copy looks good in Inkscape but shows lots of blank space in a browser window.

I think I found the problem.  Let me try again.

no attachment on your posts ...

Very strange.  Last night I uploaded and then downloaded an attachment.  Let's try again with bitmap and svg.

I added an important final step to the tutorial.  When you create and save cloud styles that you like, it's easy to transfer these to any other drawing.