PDF Underlays allow you to insert pages of PDF files into your drawings to use as references. If the PDF contains vector dat you will be able to snap to the endpoints and midpoints of lines in the PDF underlay
The underlay will appear as the bitmap data of the PDF. At different zoom level you may have to use Regen or Redraw to get the maximum resolution for the display of the underlay.
Underlays consist of two parts: the underlay style and the underlay insertion.
Before inserting an underlay in you must create an Underlay style.