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How to Install a Protective Backing Board

How to Install a Protective Backing Board

Nancy Rattenbury

Welcome back to ARTSMART

Part 2: Installing a Protective Backing Board

Over the next few paragraphs, I am going to describe the step by step process for installing a backing board to your canvas painting. Please note that I still recommend that this task be done by a professional, however, when budgets are limited, I find that it is better to be proactive rather than negligent. Much like a bodyguard, the backing board helps protect your painting’s back, especially around sharp surfaces and objects. The backing board is an essential companion for your painting.

Depending on your budget, the choice of backing material may vary. My first recommendation is ¼” coraplast (fluted polyethylene) followed by ¼” archival foam core, acid free cardboard, and then conventional cardboard. Rigidity of the backing material plays a key role in providing suitable support and protection. While mat board can protect the verso from dust and debris, it remains too pliable for support with climatic changes.

Once the backing material has been selected, there are some tools and hardware needed for installation.


Phillips screwdriver, awl, measuring tape, metal edge ruler, mat knife, marking pen, cutting board (or scrap cardboard for a cutting surface).


[#6] finish washers, [#6] ½” pan head sheet metal screws.

Before the actual installation process can begin, it is important to create a space in which to perform this task. Find a table/flat area that can easily accommodate the size of your painting and cover that surface with a clean blanket. Damages can occur if the painting is not properly protected from your work surface. To avoid any unnecessary deformations to the painting’s surface, it is also recommended that a clean cardboard layer be placed upon the blanketed surface followed by a sheet of glassine or plastic sheeting. The glassine or plastic sheeting acts as a protective interface between the cardboard work surface and the face of your painting.

Once the work surface has been prepared, the second step is to measure and cut the backing board. Place the painting face down on the work surface and measure the stretcher dimensions. Take those measurements and subtract about a 1/4” from each side. The key is not to have the backing board extend beyond the outside edge of the painting. For example: if the stretcher measures 12” x 12”; then the backing board should be approximately 11 ¾” x 11 ¾”. Use a cutting surface or scrap cardboard to cut this backing board. Position the newly cut board on the painting’s stretcher. Make sure that the backing board sits flush upon the horizontal and vertical members of the stretcher and is within the i painting’s outermost edge.

After the board has been correctly aligned on the stretcher, go ahead and mark the screw points. Depending on the size of the painting, several screws may be needed to secure the backing board onto the stretcher. For example: an 11 ¾” x 11 ¾” backing would require two screws with finish washers per corner. As dimensions increase, the vertical and horizontal measurements can be further divided into 6” increments for locating the attachment points. A good rule to keep in mind is that once the corner screws are attached to evenly space the remaining screws between those points. Placement of the finish washer and screw is just inside the perimeter of the backing board and not directly on the edge. Otherwise the board could shift overtime. See figure A

Before physically attaching the board with screws, another beneficial step is to take the awl and lightly pierce the marking points. By creating starter holes, this helps in visualizing the placement of the finish washers and screws. Please use caution when using the awl, for you don’t want to slip while piercing the board and puncture the verso of your painting. Therefore, remove the backing board to your cutting surface to make the holes and then reposition the backing board onto the stretcher for attachment. I prefer to use a hand held screwdriver which allows you to sense when the screw locks into the wood. It is important to not over tighten the screw. Otherwise the board will crease around the finish washer, especially with the foam core material.

It is very important to remember that safe handling is always recommended when hanging, moving or storing your paintings. When in doubt…just ask for assistance and with that action you are ensuring a continued future for your art work/collection. It is a little insurance toward unforeseen incidences.

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