PDF Underlay
Use a PDF page as a scaled drawing reference.
A PDF underlay displays a rendered page behind the drawing. It is a reference, not editable CAD geometry. Calibrate against a dimension you trust; the apparent page size alone does not establish site scale.
Load a reference
Choose Import → Underlays in Design. On File, browse, drop or paste an image or PDF. You must be signed in to create an underlay.
Choose and prepare a page
For a multi-page PDF, use the page arrows in the import workspace to select the required sheet. On Adjust, review crop, rotation and image appearance.
Adjust and calibrate
On Adjust, crop, rotate or adjust the image. On Size, set a physical size or calibrate two points against a known distance. Review position and rotation so the reference aligns with the drawing.
Create the underlay
On Finish, check the summary and create the underlay. It appears behind the drawing and is managed separately from drawing objects.
Change pages later
The PDF underlay keeps its source document. Multi-page PDF controls in the underlay panel let you change the displayed page. Each page can retain its own crop and calibration; verify the chosen page’s scale before using it as a reference.