How to Determine Rabbet Depth for Picture Framing

Q: How do I know whether my framing package will fit?

Add the thickness of every layer that will sit in the frame, including glazing, mats or spacers, artwork, mounting material, and backing. Compare that total with the usable rabbet depth and allow room for the materials used to secure the package.

Q: Do I measure only the artwork thickness?

No. Measure or add every component that will occupy the rabbet, not just the artwork.

What Is Rabbet Depth?

Rabbet depth is the distance from the back of the frame to the underside of the lip that goes over the art, glazing, mats, and other framing materials.

The rabbet is the recessed area along the back inside edge of a traditional picture frame. Its depth tells you how much material can sit behind the lip. This is different from the frame's face width, which is the visible width of the moulding when viewed from the front.

Read the frame profile from the side

The lip is the small inner ledge visible at the front opening. Measure vertically from the back surface of the frame to the underside of that lip. The usable space must hold the entire framing package, not only the artwork.

How to Measure Rabbet Depth

Place the empty frame face down on a clean, padded surface.
Locate the underside of the inner lip and the back surface of the frame.
Hold a rigid ruler perpendicular to the back of the frame.
Measure from the back surface to the underside of the lip.
Repeat at several points because moulding profiles and joined corners can vary slightly.

If you are shopping rather than measuring a frame you already own, use the rabbet depth listed for that specific moulding.

Calculate the Complete Framing Package

Add every layer that will occupy the rabbet. Depending on the project, that can include glazing, mats or spacers, artwork, mounting material, backing, and any fitting allowance needed to secure the package.

Total package thickness = glazing + mats or spacers + artwork and mount + backing

Compare that total with the usable rabbet depth. The package should sit beneath the lip with enough remaining room for the selected fitting method. A deep rabbet alone does not guarantee that every object or assembly method will be suitable.

How the Calculation Changes by Project

Paper Art or a Photograph

Include the glazing, every mat layer, the artwork and its mount, and the backing board. Do not calculate from the paper alone.

Canvas in a Standard Frame

Compare the full canvas depth with the usable rabbet depth. A standard frame's lip overlaps the front edge of the canvas, so confirm that this is the appearance you want.

Dimensional Artwork or Objects

Include the deepest point, mounting materials, spacers or walls, backing, and the method used to secure the assembly. Deep objects may require a different construction.

Need help establishing the artwork dimensions first? See how to measure artwork for a custom picture frame.

Rabbet Depth Worksheet

Enter the actual thickness of each component in the same unit of measurement. Use zero for layers that are not part of your project.

Component	Your thickness	Include when
Glazing	________	Glass or acrylic is used
Mat or spacer layers	________	The art is matted or separated from glazing
Artwork and mounting	________	Always include the complete mounted art
Backing	________	A backing board or panel is used
Total package thickness	________	Add all rows above
Usable rabbet depth	________	Measure or check the moulding specification

If the usable rabbet depth exceeds the package thickness, the difference is the space available for fitting and securing materials.

If the package is as deep as or deeper than the rabbet, review the frame profile or fitting plan before ordering.

Common Rabbet Depth Mistakes

Confusing rabbet depth with the visible face width of the moulding.
Measuring only the artwork and forgetting glazing, mats, mounts, or backing.
Using the overall outside depth of the frame instead of measuring to the underside of the lip.
Assuming a deep rabbet guarantees suitability for every dimensional object.
Leaving no room for the hardware or method that secures the package.
Using the specification for a different moulding instead of the exact frame being ordered.

Frequently Asked Questions

What is rabbet depth on a picture frame?

It is the distance from the back of the frame to the underside of the lip that goes over the art, glazing, mats, and other framing materials.

How do I know whether my framing package will fit?

Add the thickness of every layer that will sit in the frame. Compare that total with the usable rabbet depth and allow room for the materials used to secure the package.

Is rabbet depth the same as frame face width?

No. Face width describes how wide the moulding looks from the front. Rabbet depth describes the space available from the back of the frame to the underside of its inner lip.

Do I measure only the artwork thickness?

No. Include every component that will occupy the rabbet, including any glazing, mats or spacers, mounting material, and backing.

Choose a Frame After You Check the Depth

Once you know the package thickness, compare it with the specification for each moulding you consider. Explore the curated custom wood picture frames hub, or learn how to fit art into a wood picture frame.

Reviewed by WebPictureFrames.com framing specialists. Last reviewed August 6, 2026.