now if the solution was to import a pdf from illustrator - well that's not undo-able in xara is it - so it's back to square one [illustrator] to redo.. so why not just draw it in xara in the first place ... over the existing lines... with the shape tool if you don't have a graphic tablet, or you want micro-control...

I thought the undo was important.....

[edit - and the illustrator effect is still artificial - 'wave' amplitude/frequency are patterns, and it will tend to show; humans don't draw like that unless they mean to for a reason...]