norwichpaul

Sorry to continue on with this but am I correct in thinking that if I draw a line in paint.net with a length of 20 mm and I then print it and the printed result is 27 mm in length - this is because the image dpi is not the same as my printer dpi? Which is fine but does this mean that I can draw to a scale of say 1:50 and provided I can match up the two dpis, the printed image is to a scale of 1:50? Thanks in anticipation, Norwichpaul