18x24 Picture Frame Mounting & Backing Board

Choose mounting and backing board for the project

Backing board supports the artwork package and helps close the rear of a frame. Mounting board provides a surface for an appropriate attachment method. One board may sometimes perform both roles, but the board and mounting method should be selected separately according to the artwork and the level of permanence the project allows.

Board option	Useful for	Important consideration
Regular white foam core	Lightweight support for replaceable posters, prints, and general framing projects	Available in 3/16-inch and thinner 1/8-inch versions; it is not presented as a conservation material.
Acid-free foam core	Photographs, prints, and projects that call for an acid-free facing material	Available in 3/16-inch and 1/8-inch versions; confirm the complete framing package and mounting method.
Black acid-free foam core	Projects where a dark board edge or exposed black backing supports the presentation	The current product is 3/16 inch thick and should be selected for color as well as package fit.
Self-adhesive foam core	Permanent mounting of suitable, replaceable media	The adhesive is one-time and non-repositionable. Do not use it when reversible mounting is required.
Cardboard	Economical backing for general-purpose projects	The current board is 1/8 inch thick and is not an acid-free preservation option.
Acid-free foam core and matboard	A two-board package with 3/16-inch foam core and separate 1/16-inch four-ply matboard	The two pieces total approximately 1/4 inch before the artwork, glazing, or other components are added.
Gatorfoam	Projects that benefit from a harder, more rigid mounting surface	The current 3/16-inch product is not a conservation material.

Watch: Backing board types explained

See how regular foam core, acid-free foam core, black foam core, matboard, cardboard, and Gatorfoam compare before choosing a board for the artwork, mounting method, and available frame depth.

View the Backing Board Types Explained video page.

Choose 1/8-inch or 3/16-inch board

Board thickness affects rigidity and physical fit. A 3/16-inch board provides more thickness, while a 1/8-inch board saves 1/16 inch when the frame has limited interior depth. Thin board is not automatically the better fit: add the artwork and every selected component before choosing.

The complete package may include glazing, mats, spacers, artwork, mounting material, backing board, and fitting hardware. Compare their combined thickness with the frame rabbet. The rabbet depth guide explains how to check that space.

Keep valuable artwork mounting reversible

Self-adhesive board creates a permanent bond and does not allow a second placement attempt. Reserve it for media that can appropriately be mounted permanently. Original artwork, valuable photographs, documents, and irreplaceable items generally call for a qualified reversible attachment method rather than direct pressure-sensitive adhesive.

Acid-free board describes a material property; it does not by itself make every mounting method or complete frame package suitable for conservation work. Consider the artwork, attachment method, mat, glazing, backing, environmental exposure, and the ability to remove the artwork later.

Order the correct board dimensions

Order the board to the dimensions required by the frame package, not automatically to the visible image size. In a typical matted paper-art package, the board commonly follows the outside dimensions of the mat and the frame opening. Enter the exact width and height above to compare available products and current prices.

Maximum dimensions vary by product. The 1/8-inch foam boards and the foam-core-plus-matboard combination are currently limited to 40 x 60 inches, while several 3/16-inch products allow larger dimensions. The size controls on this page show which options are available for the dimensions entered.

Complete the picture framing package

Backing is one part of the complete assembly. Compare custom picture mats for spacing and presentation, glass and acrylic glazing for the front of the package, and picture framing supplies for fitting and finishing components.

For material-specific demonstrations, visit the picture framing video library for videos about regular foam core, acid-free foam core, black foam core, matboard backing, cardboard, and Gatorfoam.

Mounting and backing board questions

What is the difference between mounting board and backing board?

Backing board supports and closes the rear of a framing package. Mounting board is the surface used with an appropriate method to hold the artwork. Depending on the project, one board may serve both functions.

Should I choose 1/8-inch or 3/16-inch foam core?

Choose according to the required support and available rabbet depth. The 1/8-inch option saves 1/16 inch of package depth; the 3/16-inch option is thicker. Add every frame-package layer before deciding.

Can I use self-adhesive foam core for original artwork?

Self-adhesive foam core creates a permanent, non-repositionable bond, so it is not appropriate when the artwork must remain removable or reversibly mounted.

Is Gatorfoam a conservation backing board?

No. The Gatorfoam currently offered here is a rigid mounting and backing material, but it is not identified as a conservation material.

Framing guidance reviewed by Web Picture Frames framing specialists. Last reviewed August 2026.

Picture Frame Mounting and Backing Board

Acid-Free Foam Core Board 3/16

Thin Acid-Free Foam Core Board 1/8

Black Acid-Free Foam Core Board 3/16

Regular White Foam Core Board 3/16

Thin Regular White Foam Core Board 1/8

Self-Adhesive Foam Core Board 3/16

Corrugated Cardboard Backing Board 1/8

Acid-Free Foam Core and 4-Ply Matboard Set 1/4

Gatorfoam Rigid Mounting Board 3/16