Overview

The Overlay tool lets you capture a snapshot of any rectangular area on a plan page and place it as a floating, repositionable layer on top of the same document. This makes it easy to compare two areas side-by-side, highlight revisions, or stitch plan sections together — all without leaving the document viewer.

Overlays are created from the annotation toolbar in any PDF-based document. Once placed, they behave like other annotations: they can be moved, resized, edited, or deleted, and they are saved to the plan view or takeoff automatically.

Requirements

• Plan must be a PDF document (the tool is hidden for other file types)

• Workspace must be on the Pro plan (free tier sees a disabled button with an upgrade prompt)

• The document must have finished processing (static images must be ready)

Overlay Types

When you click the Overlay button, a modal lets you choose one of three overlay types before you draw.

Colorized

Captures the selected area and tints all dark pixels with a color you choose. The background (white/light areas) is made transparent so the underlying plan shows through.

Best for: Color-coding and visually tagging specific regions of a plan, comparing two areas of the same drawing with different color indicators.

How it works:

1. Select Colorized in the overlay type tabs.

2. Pick a color using the inline color picker.

3. Click Confirm to enter drawing mode.

4. Click and drag on the plan to select your reference area.

5. The overlay appears as a color-tinted, transparent copy of that area.

Comparative

Captures the selected area and applies a difference-style blend: additions appear in red, deletions appear in blue. This is useful for spotting what changed between two plan revisions placed on top of each other.

Beta feature — Comparative overlays support repositioning and scaling but do not yet support rotation.

Best for: Identifying differences between plan revisions; quality-control checks on updated drawings.

How it works:

1. Select Comparative in the overlay type tabs.

2. Click Confirm to enter drawing mode.

3. Click and drag over the area you want to capture.

4. The overlay uses a blend mode to highlight additions (red) and deletions (blue) against the underlying plan.

Opaque

Captures the selected area as a fully solid image with no transparency. The background is preserved as-is.

Best for: Stitching plan sections together, covering/replacing a region of a document, or inserting a plan fragment without any blending.

How it works:

1. Select Opaque in the overlay type tabs.

2. Click Confirm to enter drawing mode.

3. Click and drag to select your reference area.

4. The overlay is placed as a solid, opaque image.

Step-by-Step: Creating an Overlay

1. Open a PDF-based plan in the document viewer.

2. Click the Overlay button in the annotation toolbar (difference/layers icon). If the button is grayed out, see FAQ below.

3. In the Create Overlay modal, select an overlay type (Colorized, Comparative, or Opaque).

4. For Colorized overlays, pick your desired color.

5. Click Confirm.

6. A context banner appears: "Click and drag to select your reference area. The overlay will be created as a separate item."

7. Click and drag on the plan to draw a rectangle around the area you want to capture.

8. The overlay is created and placed on the canvas. The tool automatically switches back to the pointer so you can immediately reposition or resize the overlay.

Editing an Existing Overlay

To change the type or color of an overlay after it has been placed:

1. Double-click the overlay on the canvas to open the Edit Overlay modal.

2. Switch to a different type tab or change the color (for Colorized).

3. Click Confirm to apply. The old overlay is replaced with a new one and the change is recorded in undo history.

Note: If editing fails, delete the overlay and recreate it from scratch using the steps above.

FAQ

Can I use overlays on non-PDF files?

No. The Overlay tool is only enabled for PDF documents. For other file types, the button is not shown in the toolbar.

Does the overlay update automatically if the source plan changes?

No. An overlay is a static snapshot taken at the moment of creation. If the underlying plan is updated, you need to delete the old overlay and create a new one.

Can I rotate a Comparative overlay?

Not yet — rotation is not supported for the Comparative type. Colorized and Opaque overlays can be freely rotated after placement.

Can I undo creating or editing an overlay?

Yes. Both creation and editing are recorded in the annotation undo history. Use Ctrl+Z / Cmd+Z to undo.

Is the overlay saved to the plan automatically?

Yes. Overlays are saved as markup annotations and persist to the database automatically when they are created or updated.

What's the difference between Colorized and Comparative?

Colorized tints the captured image with a single color of your choosing — good for highlighting. Comparative uses a blend mode to show pixel-level differences between the overlay and what's underneath it — good for spotting revisions.