One issue new users see in AutoCAD P&ID, is the boxes around instruments and other items. These boxes provide masking for text within the instrument bubbles, but are displayed by default when plotting.
AutoCAD P&ID uses an AutoCAD feature called wipeouts (command WIPEOUT) to hide the edges of bubbles. Each wipeout has a frame that show the boundary. This frame is what shows up in the drawing.
To hide the frame we have a couple options.
1. We can turn the wipeout frames off by using WIPEOUT, F (for frames), and OFF.
2. In 2013, AutoCAD introduced a new option, Display but not plot. You may select that, or use the new system variable, WIPEOUTFRAME =2 to not plot the frames.