Autocad (it is the eternal enemy...) is able to manage the printing without changing the existing drawing.
But I experienced a new problem; when asking to a friend to get more thick lines (using Autocad) he saved the drawing using a ... new layer's color!
Yellow means a thicker line (in autocad) while means I have to change the property of the layer when opening in qcad...
![Sad :(](./images/smilies/icon_sad.gif)