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Priming Wood Panels With Acrylic Gesso

Priming Wood Panels With Acrylic Gesso

A wood panel is a better painting substrate because it is less susceptible to expansion and contraction than flexible supports, like canvas. The movement of these flexible supports can result in cracks and damage to the artwork created on them.

Ampersand offers several ready to use sealed and primed panels, but for artists that prefer to prime their own painting panels, enjoy working with a natural wood texture, or need strong support for encaustic, collage, or mounting, Ampersand also offers three unprimed wood panel options: Hardbord, Unprimed Basswood, and Birch Wood Panel.

Commonly, artists ask us if unprimed wood panels need to be sealed. The answer is yes. If wood is not sized or sealed properly before applying gesso, yellowing can occur. This is because water (a solvent) can cause acids that occur naturally in wood to migrate to the surface. In fact, it is extremely important to properly seal all unprimed wood substrates to prevent support-induced discoloration that can cause your paint film to yellow over time.

Materials List:
Ampersand Hardbord, Unprimed Basswood, or Birch Wood Panel
Golden® Gloss Medium or Gamblin® PVA Size
Acrylic gesso
2”-3” flat bristle brush
Small foam roller (optional)
Sanding block with fine 400/grit sandpaper
1”-2” painter’s tape (optional)

 

Step 1: Size and Seal the Wood
A size is a thin solution (often a weak glue) that is brushed directly onto a support. When using acrylic gesso as the ground layer, sizing or sealing a wooden panel is recommended to protect your painting from yellowing due to support-induced discoloration.

Because of the lower density of plywood panels like Basswood and Birch, the sealer should be applied to the front and back to ensure they are fully protected. Due to the high density of Hardbord, this panel only requires sealing the front of the painting surface.

The products we recommend to seal wood panels are:
Golden® Gloss Medium OR
Gamblin® PVA Size

Using a 2”-3” flat bristle brush, apply the sealer to the front of the panel. If using a plywood panel, apply it to the back as well. Allow to dry completely and follow with an additional coat. Do not sand between layers of the sealer. Before applying acrylic gesso, allow to completely dry so that the sealer can coalesce into a uniform film for maximum protection.

 

Step 2: Protect and Prepare the Cradle 
Ampersand unprimed panels are available with wood cradles in various depths. Artists may choose to paint the cradles or leave them untouched and allow the natural beauty of the wood cradle to show.

If you prefer to paint the cradles, be sure to seal the cradle first, as it is also constructed of unprimed wood. Or, if you choose not to paint the cradles, cover the sides of the panel with painter’s tape, up to the edge of the surface, to protect the wood from paint and gesso.

 

Step 3: Apply the Acrylic Gesso
Acrylic gesso is a flexible liquid ground that protects and gives “tooth” to wood panels, which promotes good paint adhesion. It comes ready-to-use and can be applied with a brush, roller, putty knife, or even sprayed on. Follow the directions provided with the gesso product that you are using for product-specific information. For this example, we will share instructions of application using a brush and roller.

Using a 2”-3” brush, begin by working the gesso back and forth with the brush in one direction and then in a cross direction with a little pressure so that the gesso penetrates the panel better. If using Unprimed Basswood or Birch Wood Panel, remember to gesso both the front and back of the panel.

If you sealed the panel’s cradles, you could apply gesso to the cradles at this time.

 

Step 4: Finish
After the first coat of gesso is dry, smooth out any rough spots with light grade sandpaper. Apply a second coat of gesso with the foam roller for a more even application, (a brush may also be used if you do not have a foam roller). Allow it to dry and then sand again. For best results, apply a minimum of 2 coats of gesso and sand in-between. Subsequent layers of gesso will produce an even smoother painting surface. Follow the directions provided with the product that you are using for the recommended number of coats. For spray-application, you may need to apply more than 2 coats to achieve a film similar to a brush application.

For plywood panels like Basswood or Birch, follow the same instructions, but for each additional coat to the panel surface, apply the same number of applications to the back.

Once the final gesso coat is dry, your panel is ready!

6 comments on “Priming Wood Panels With Acrylic Gesso”

  1. Avatar Daryl Reimer says:

    In other articles I have read that it is recommended to use GAC100 to seal wood panels prior to applying Gesso.

    How is GAC100 different from PVA Size and Gloss Medium.

    1. Avatar Dana Brown says:

      Hello – Thank you for your question.
      In the past, we recommended GAC 100 from Golden and PVA Size as options for sealing wood to prevent Support Induced Discoloration (SID). This recommendation was based on our own testing as well as information shared with us by the product manufacturers and chemists. Not too long ago, Golden revised their recommendation of GAC 100 as a result of new testing data and so we revised our recommendation as well. They now recommend their Gloss Medium for sealing wood to prevent SID. GAC 100 will still work, but the barrier created by Gloss Medium blocks tannin and other acids even better. Golden offers some additional information regarding this in the product pages of their site. PVA Size has performed well in our testing (as has GAC 100) and both of these products can still be used for preventing SID. All three of these products help to prevent migration of the naturally occurring acids in wood, from finding their way into your priming and painting layers. Thank you – Dana at Ampersand

  2. Avatar Silky Hart says:

    Hello. Does the Gloss Medium have to be Golden or an it be Liquitex Gloss Medium?
    Thank you,
    Silky Hart

    1. Avatar Dana Brown says:

      Hello – Yes, Liquitex will work also. Thanks!

  3. Avatar Ellee says:

    Can Golden Matte Medium be used instead of the Gloss Medium?

    1. Avatar Dana Brown says:

      Thanks for your question! The amount of impurities that are blocked by an acrylic medium varies greatly and they don’t all perform at the same level. Golden’s Gloss Medium has been shown to do a better job at preventing Support Induced Discoloration than any other Golden medium. Here is a link to an article about their testing: https://justpaint.org/blocking-support-induced-discoloration/

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