# PDFATTACH Command [GstarCAD 2022](Help%20System/GSTARCAD/2022/Index.md) → [Commands](Help%20System/GSTARCAD/2022/Commands/(Commands).md) → [P](Help%20System/GSTARCAD/2022/Commands/P/(P).md) ## Function Description: This command is used to insert a PDF file as an underlay into the current drawing. When you attach a PDF file as an underlay, you link that referenced file to the current drawing. Any changes to the referenced file are displayed in the current drawing when it is opened or reloaded. The Select Reference File dialog box is displayed. Once you select a PDF file, the [Attach PDF Underlay dialog box](Help%20System/GSTARCAD/2022/Commands/03%20Dialog%20Boxes/Attach%20PDF%20Underlay%20Dialog%20Box.md) is displayed. ## Command Access: > **Icon:** >  > **Menu:** Insert \> PDF Underlay > **Ribbon:** Insert \> Reference \> PDF Underlay > **Toolbar:** Insert \> Insert a PDF Underlay > **Command:** PDFATTACH > **Alias:** / **Command Prompts: /**