How to take print of Drawing while I have added some multi lines over existed lines of Drawing.

I am doing some modifications in P&ID and PFD Drawing. The new lines multi lines are visible but the existing lines at drawing are becoming very thick. resulting in unable to understand the drawing. kindly help to resolve this issue. I have attached the reference drawing. 

Picture 1 is the print out of my System 

Picture 2 is the Print out of one of my colleague ( Who don't have any issue in Printing ) 

1.                                                                                                      2.