ATTACH Command In AutoCAD : Inserts References To External Files Such As Other Drawings, Raster Images, Point Clouds, Coordination Models, And Underlays

If you need a clear, step‑by‑step guide to using the ATTACH command in AutoCAD — what it does, how to use it, why it sometimes fails and what alternatives exist — this article explains everything in beginner‑friendly detail, with practical tips and an FAQ.

Table of Contents

What is the ATTACH command?

The ATTACH command in AutoCAD inserts references to external files into your drawing. These can include other DWG drawings (as external references / xrefs), raster images (JPEG, PNG, TIFF), PDF underlays, Point clouds (RCP/RCS), and coordination models (Navisworks). Using attachments keeps large or shared content external to the host drawing so you can update or reuse references without duplicating data.

Key benefits:

Keep the main drawing file smaller and more manageable.
Allow multiple users to work on source files independently.
Control visibility, scale, and layering of referenced content.

When to use ATTACH vs XREF vs INSERT

Use ATTACH (or the Attach dialog) for a broad set of external files (images, PDFs, point clouds, coordination models and DWGs).
Use the XREF command or palette when you want full control over DWG external references (Attach vs Overlay, bind/unload/reload).
Use INSERT to embed a DWG or block directly into your drawing (this makes the content part of the host drawing).
Use IMAGEATTACH or PDFATTACH if you prefer dedicated commands for images or PDFs.

General rule: choose xref/attach when you want a live external link; choose insert/bind when you want the content permanently inside the file.

How to use ATTACH — Step by step

H3 Using the Attach dialog (recommended for beginners)

Open your drawing.
Type ATTACH on the command line and press Enter, or go to the Insert tab > Reference panel > Attach.
In the Attach dialog, select the file you want to attach (use the file‑type dropdown to choose images, PDFs, DWG, point clouds, etc.).
Click Open. The dialog will present attachment options (insertion point, scale, rotation, path type).
Choose whether to specify insertion point on screen or enter coordinates, set scale and rotation, then confirm.
The reference appears in the drawing. Use Zoom Extents if it’s not immediately visible.

H3 Quick command-line shortcuts

Type ATTACH — generic attach dialog for many file types.
Type IMAGEATTACH — attach raster images.
Type PDFATTACH — attach PDF underlays.
Type POINTCLOUDATTACH — attach RCP/RCS point clouds.
Type XREF or -XREF — manage DWG external references with more control.

H3 Attaching common file types — quick notes

DWG: Use XREF or ATTACH; you’ll be able to choose Attach or Overlay.
Raster images (JPG/PNG/TIF): use IMAGEATTACH or ATTACH; options include clipping and image frame.
PDF: use PDFATTACH or ATTACH; you can attach pages, set clipping, and control insertion units.
Point clouds (RCP/RCS): use POINTCLOUDATTACH and set insertion, scale, and indexing options.
Coordination models (NWD/NWC): supported via the Attach dialog (as coordination models) if your AutoCAD version includes that feature.

Attach dialog options explained

Insertion point: specify on‑screen or type coordinates. If off-screen, use Zoom Extents.
Scale: set X/Y scale or choose “Specify on screen”. Ensure units match (see Units conversion below).
Rotation: set rotation angle at insertion.
Path type (important): Full, Relative, or No path. This controls how AutoCAD finds the external file later. Use Relative for project folders you move together.
Attach vs Overlay (for DWG xrefs): Attach nests with downstream xrefs; Overlay does not become nested in host xrefs.
Preview & Page selection (PDF): choose page and crop while attaching.
Clipping: clip attached images, PDFs, or xrefs to limit visible area.

Units and scale: what to check

Confirm the source file’s units (millimeter, meter, inch). Mismatched units cause wrong scale on insertion.
Use the INSERT/ATTACH dialog options or the SCALE command after attaching to correct size.
If attaching PDFs or images, consider using PDFIMPORT or raster scale references if precise scaling is required.

Common problems and fixes

Problem: Attached file does not appear

Fix: Use Zoom Extents. Check layers are On/Thawed and not frozen. Ensure the object is not on a locked layer. Check IMAGEFRAME is set to 1 (to see image frames).

Problem: Broken reference path / reference not found on another computer

Fix: Use the XREF manager to change path, or set REFPATHTYPE to Relative before attaching. When sending files, use eTransmit to package drawing + references.

Problem: Attachment is the wrong size

Fix: Check source file units and reinsert with correct unit conversion; use SCALE or reattach with correct scale.

Problem: Unsupported file type

Fix: Convert the file to a supported format (e.g., convert unusual raster to TIFF/JPEG, or export Revit/other models to an accepted format). Use PDFATTACH, IMAGEATTACH, or export to DWG as needed.

Problem: Very slow drawing or high memory use after attach

Fix: Reduce Raster image resolution, clip or crop attachments, unload heavy xrefs when not needed, use BOUNDARY CLIP or lower point cloud density, or detach until needed.

Problem: Need to make attached content editable

Fix: For DWG xrefs, use XREF > Bind (Bind or Insert) to make the geometry part of the host drawing. For images/PDFs, use PDFIMPORT or IMAGE trace methods to convert to objects (results may require cleanup).

Problem: Units or coordinate offset when working with GIS or Revit files

Fix: Use consistent Coordinate systems, or apply coordinate transformations using GEOGRAPHICLOCATION, MAPCSASSIGN, or rebase coordinates and attach with correct insertion point.

Alternative commands and workflows

XREF / -XREF: Advanced management of DWG external references (attach/overlay, unload, reload, bind).
IMAGEATTACH: Direct command for raster images.
PDFATTACH: Direct command for PDF underlays.
POINTCLOUDATTACH: Attach and manage RCP/RCS point clouds.
PDFIMPORT: Convert PDF geometry to AutoCAD objects.
INSERT: Insert blocks or DWGs as embedded content (not linked).
BIND / INSERT (from Xref Manager): Convert Xref to permanent objects in the host drawing.
eTransmit: Create a packaged set of the DWG plus all referenced files for sharing.
ATTACH + clipping/REFEDIT: Edit portions of xref content with REFEDIT (careful with nested xrefs).

Practical tips and best practices

Use relative paths for references when working in project folders to avoid broken links when moving the project.
Maintain a clear folder structure: /drawings, /images, /pdfs, /pointclouds. Keep paths short and consistent.
Prefix xref layer names (or use the Layer States Manager) to avoid layer name conflicts.
Unload heavy attachments when not needed to improve performance.
Use Clip for images/PDFs/xrefs to limit the visible area and reduce visual clutter.
Use eTransmit before sending a drawing to clients or collaborators — it packages all attachments.
For collaborative projects, agree on a reference file naming and path policy.
Regularly audit and purge your drawings to remove unused references and reduce file size.

Examples — before and after

Example 1 — Site plan with floor plan xref

Before: Base site drawing shows only property outline.
Action: Use ATTACH or XREF to attach the building floor plan DWG at the correct insertion point with Relative path.
After: Floor plan appears at correct location; updates to the source DWG reflect automatically in the host drawing.

Example 2 — Scanned as-built image

Before: You have a scanned site photo/JPEG you need to trace.
Action: Use IMAGEATTACH to insert the JPEG, set insertion point and scale (verify units), clip to area of interest.
After: The image is placed in the background and you can create CAD geometry over it; unload when done.

Example 3 — PDF underlay for measured drawing

Before: Received a multi-page PDF plan.
Action: Use PDFATTACH, select the page and clip as needed; use PDFIMPORT if you need editable vector geometry.
After: You can display the PDF as an underlay or import its geometry for editing.

FAQ

What file types can the ATTACH command load?

ATTACH supports common formats including DWG, DWF, DGN, PDF, raster images (JPG/PNG/TIF/BMP), point clouds (RCP/RCS), and coordination models (Navisworks) depending on your AutoCAD version. Use dedicated commands (IMAGEATTACH, PDFATTACH, POINTCLOUDATTACH) when available.

Why can’t I see the attached file even after attaching it?

Common causes: the reference is off‑screen (use Zoom Extents), the layer is off/frozen/locked, insertion scale is wrong, or IMAGEFRAME is off. Check layer visibility, zoom, and insertion scale.

How do I change the path type (relative/full) of an attached reference?

Open the XREF manager (for DWG xrefs) or use the Attach dialog. You can also change path settings with the REFPATHTYPE system variable or by detaching and reattaching with the desired path type selected.

How do I detach or unload an attached file?

Open the XREF manager (for DWGs) or the Reference/Image manager, select the reference and choose Unload, Detach, or Bind as needed.

How can I make an attached DWG editable inside my drawing?

Use XREF > Bind (or the XREF manager) to bind the xref into your drawing. Choose Bind or Insert depending on whether you want layer names merged or prefixed.

How do I include attachments when sending a drawing to someone else?

Use eTransmit to package the DWG and all referenced files into a zip or folder that preserves relative paths and ensures recipients can open the drawing with attachments intact.

Can I convert an attached PDF or image to editable CAD geometry?

Yes — use PDFIMPORT to bring PDF vector data into AutoCAD. For raster images, you can trace manually or use raster-to-vector tools (AutoCAD raster design or third‑party utilities).

Why does an attachment slow my drawing down?

Large raster images, high‑density point clouds, or many nested xrefs can consume memory and slow performance. Fixes: Unload heavy references, clip images/xrefs, reduce raster resolution, or work in a simplified file with needed references only.

What is the difference between Attach and Overlay for DWG references?

Attach causes the xref to be nested into downstream references (it becomes part of the chain). Overlay displays the xref in the current drawing only and prevents it from nesting into other drawings that reference this drawing.

I moved my project folder to a new computer; attached files are missing. What should I do?

Ensure you moved the referenced files maintaining the same relative folder structure, or use the XREF manager to point references to the new locations. For future projects, set Relative paths and use eTransmit to package files for transfer.