Another tip on a new feature in CorelCAD May 2012 update release - using the new PDF underlay functionality in CorelCAD.

The .DWG file format supports referenced PDF documents as underlay in the CAD model. With that capability you're able to display content that is only available as published PDF within your CAD drawings.

With PDF underlay functionality in CorelCAD, there's more you can do with PDFs as a drawing component:
You can

1. insert multipage PDFs or selected pages from a PDF as a reference
   
    
2. control the content of the PDF file and its appearance by layer (so the PDF contains layers)
   
    
3. clip a referenced PDF to only display selected parts of the original file
   

The PDF will not be modified by any of the CorelCAD PDF underlay features so full integrity of the referenced file is always maintained.

With a PDF underlay you can work as precise as with any drawing object in the CAD file. The drawing objects in a PDF underlay are recognized by CorelCAD which means you can use snap tools to align new drawing components to those objects in the PDF underlay.

Make sure you turn "ESnap" and "ETrack" on in the status bar so that you can leverage the vector objects in the PDF as snap points for new elements!

...a great way to repurpose and enhance existing published CAD files, fully eliminating the need to redraw from scratch and leveraging the full precision of the existing PDF content.