There is no setting which directly makes area boundary lines not print. That said, there are multiple ways to effectively make the lines not visible when printing which are fairly quick to set up. Here are two:
- The fastest solution is to change their setting in the Line Styles menu just prior to printing. You could make them a line weight 1 and black color with a solid pattern, that would make them quite discreet. This will not "turn them off" explicitly but, assuming your area plans are in black-and-white, the area boundary lines will blend in with other lines.
- You could also set up one or more View Templates in which you have unchecked the <Area Boundary> subcategory under the Lines row in the Model Categories tab. This would truly "turn off" the area boundary lines. This method takes a little more time since you would have to apply the View Templates to each area plan you are printing, but it would truly make the area boundary lines invisible.