# PDF Underlay [GstarCAD 2020](Help%20System/GSTARCAD/2020/Index.md) → [User Guide](Help%20System/GSTARCAD/2020/User%20Guide/(User%20Guide).md) → [Additional Pages](Help%20System/GSTARCAD/2020/User%20Guide/Additional%20Pages/(Additional%20Pages).md) ## PDF Underlay **Menu:** Insert\>Reference\>PDF Underlay **Command Entry:**PDFATTACH If you receive project drawings in the form of a PDF file, you can reuse that PDF data in your own GstarCAD drawing files. For example, imagine that you are a landscape designer and you receive a PDF file for this building project. This particular sheet includes a floor plan that you want to use as starting point for your landscape design.  Attaching a PDF as underlay In GstarCAD you can attach a PDF file as an underlay to your drawing. Access to PDF Underlay at Insert tab on the ribbon or type\> PDFATTACH command.  If the PDF includes multiple sheets, you simply choose the appropriate one during the attach operation. You can define some parameters like insertion, rotation and scale point before attaching the PDF. You can use the underlay as a reference background after it is attached.   Then you can start drawing or placing geometry at specific point of the underlay.  What's more, you can adjust the underlay display like contrast, fade, monochrome, and colors for background through the properties palette.  --- Gstarsoft Co.,Ltd ## Other versions with matching text [GstarCAD 2016](../../../2016/User%20Guide/Additional%20Pages/PDF%20Underlay.md) · [GstarCAD 2019](Help%20System/GSTARCAD/2019/User%20Guide/Additional%20Pages/PDF%20Underlay.md)