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All Things Ampersand

Painting on Panel: Resources for Hardbord

In our “Painting on Panels” series, I’ve been sharing a lot of tips on working on wood panels.  To keep it all in one place, this is a list of resources for understanding wood panels and the best practices in working on them for producing long lasting art.

Working with Masonite — Read about what makes Ampersand’s hardboard different than Masonite, archival to use and the differences between other panels in the market.


Solid Wood vs. Manufactured Wood Panels —  The top 4 things an artist should consider when choosing a panel type.


Differences between HDF & MDF — What to look for in choosing a panel, whether it is hardboard, HDF or MDF.  Understanding the properties of each and how they will effect your artwork long term.


Cradling and Supports — Why it’s a good idea to brace large manufactured panels.


Sizing — Why it is important to size panels before priming and how to choose the proper products for good adhesion.


Oil Priming — All raw wood panels need to be sized and primed before painting. This outlines the basics on priming with an oil ground and which products to use for the best results.  


Acrylic Priming —  Step by step instructions for using an acrylic dispersion groung to prepare wood panels.

Support Induced Discoloration —  The reasons that SID occurs and what you can do to prevent it.  

Take note that Hardbord and Unprimed Basswood are on sale now up to 50% off list price through the end of February.  Here is a list of the participating dealers: www.ampersandart.com/retailers2/promo-retail

All things Ampersand, 

Karyn Meyer-Berthel 
Artist & Social Media Specialist 
Ampersand Art Supply 

Click here to explore the full selection of Ampersand panels and tools.

Painting on Panel: Support Induced Discoloration

You may have heard the term “Support Induced Discoloration” or SID in relation to sealing panels or even gessoing a canvas.  And SID is the one reason that Ampersand encourages sealing panels before priming, but what does it really mean and how does it effect art long term?

Support Induced Discoloration is a relatively new concept to the art world, new because acrylic dispersion paints are new.  Support Induced Discoloration occurs when acrylic paints change color due to pulling up toxins or residue in the substrate.  The fluids in the paint leach into the substrate, through the primer and pull up the residue, leaving behind particulate in the paint that discolors it.  This is most apparent in transparent gels and mediums but also occurs to pigmented paint.  Gesso or primer is not sufficient in preventing discoloration, so sealing or sizing is always recommended.  

You can prevent SID from affecting your own work by properly sealing wood panels before use.  For more information on Sealing (or sizing) panels, refer to our previous post:
Painting on panel sizing.  OR, You can purchase one of Ampersand’s already sealed and primed panels, such as Gessobord™, Encausticbord™, Claybord™, Aquabord™ or Scratchbord™.  All of these panels have been sealed with Ampersand’s Archiva-Seal™ technology.

In the early 1990’s, Golden Artist Colors did some significant research with Buffalo State College to discover support induced discoloration and test the degrees of discoloration on different supports, with different acrylic mediums and primers.  The results from these experiments led to what we know today about SID.  

“SID contamination often goes undetected. In most cases, the paints applied contain a sufficient level of pigment, thus a strong enough color, to conceal the yellowing. However, in a transparent glaze and especially in thick translucent gel layers, SID becomes quite noticeable. SID can transform the appearance of an Ultramarine Blue glaze into a lower chroma, greenish color. Gesso alone will not stop SID, and different gels and mediums have varying degrees of blocking capabilities. The best product Golden Artist Colors produces to prevent SID is GAC 100. This thin medium works best when 2 or more coats are applied directly into the support. Once dry, the canvas can then be primed and subsequently painted with less potential for discoloration. Pre-primed canvases can be sealed with GAC 100 as well. Apply one or two coats onto the surface, and follow with at least one coat of gesso to regain tooth if needed.” — From the GAC website

Golden has neatly packaged the effects of SID on a masonite panel below in video format.  You can see for yourself in a few minutes how drastically a piece of art can change in a matter of weeks if the work is not sealed properly.


All things Ampersand, 
Karyn Meyer-Berthel 
Artist & Social Media Specialist 
Ampersand Art Supply 

Click here to explore the full selection of Ampersand panels and tools.

Painting on Panel: Oil Priming

For those of you that purchase our museum quality panels, Aquabord™, Encausticbord™, Pastelbord™, Gessobord™ or Claybord, we complete the sealing and priming for you on the front of the panel.  However, for anyone who is choosing to do their own sizing and priming for oil painting, these instructions for priming in oil will be helpful.  Our Hardbord panel and the Unprimed Basswood Artist Panel both require sealing and priming before use.

All wood panels must be sealed (also known as sizing) before painting in order to put a barrier between the naturally occurring chemicals in wood and the painting ground. Support Induced Discoloration (SID) occurs when a panel is not properly prepared and these chemicals leach through to the paint on the surface. By choosing a denser panel with a low acid content, an artist greatly reduces their risk of SID. However, all wood panels should be sized (sealed) and primed before painting to ensure their longevity. 

Gamblin® Oil Painting Ground is our first choice in a good quality oil primer. However, the following instructions are virtually interchangeable with a number of other oil painting grounds if there’s one you like better or have more readily available. Gamblin® Oil Painting ground contains an alkyd resin vehicle that allows it to dry within a matter of hours. A number of other pre-made oil primers are also available and generally, they are made up of a white pigment, linseed oil and driers or solvents. Primers that use alkyd resin binder instead of linseed oil dry faster and are non-yellowing and more flexible than traditional grounds. Both may be applied in the same manner with either a large putty knife or a large stiff bristle brush. If you are using a traditional oil primer, it may need to be thinned with Gamsol® to a workable consistency enabling easy application over the sized panel. Never add oil to a primer. Its leanness must always be preserved.

Step 1 – Size and seal the wood
A size is a thin solution (often a weak glue) that is brushed directly onto a support. Sizing or sealing Ampersand’s uncoated panels is recommended to protect against SID. In fact, it is extremely important to properly seal any and all un-primed wood substrates to prevent support-induced discoloration that can cause your paint film to yellow over time. Hardbord™ is manufactured using Aspen fibers, a wood with a very low acid content, but still needs to be sized and sealed. The Natural Wood Panel™ and Unprimed Basswood panels are made with a thick basswood plywood top that has been sanded ultra-smooth. They are both seamless and knot-free and provide a perfectly smooth and uniform painting finish. When you apply the size and primer to the basswood surface, you won’t experience the raised wood grain fibers that can happen with some other rougher types of plywood; the surface stays nice and smooth. The basswood panels have solid wood cradles and braces that may be more susceptible to moisture and environmental changes than the birch plywood cradles we use on the Hardbord™. Therefore, Ampersand recommends that you prime both the front and back of the Basswood top to ensure long-term stability of the panel.  The best products we have found to seal wood are Golden® GAC100 [2 coats]  and Gamblin® PVA Size [4 coats].
Apply Golden® GAC100 directly to the basswood or hardboard surface with a 2″ paintbrush or putty knife. Apply to the front and back if applicable. Allow the GAC100 to dry completely and follow with an additional coat. Do not sand between layers. Before applying oil primer or the painting ground, allow the GAC100 to dry for 1-3 days so that the sealer can coalesce into a uniform film for maximum protection. If you’re using Gamblin® PVA Size, use 4 coats and follow the same application instructions as for the GAC100.

Step 2 – Protect and prepare the cradle
Hardbord™ is available in either a flat 1/8″ panel, with a 3/4″ cradle, or with the 2″ DEEP cradle. The Natural Wood and Unprimed Basswood panels are available in both a 7/8″ cradle and 1.5″ cradle profile. You have the choice of painting all the way around the cradle or leaving the natural wood showing for framing purposes. Be sure to size and seal the bare wood if you want to paint completely around the edges of the cradle. Or, to protect the wood from paint and primer, cover the sides of the panel with painter’s tape up to the edge of the surface. Do not remove the tape until the painting is finished. Painter’s tape does not leave a sticky residue like many household masking tapes that can be difficult to remove, and will leave a pristine surface underneath when the painting is complete. 

Step 3 – Apply the Oil Painting Ground or Oil Primer
Begin by mixing small amounts of Gamsol® with the primer to thin if necessary. You can test the right consistency by picking up the paint with a knife and shaking it gently. If it falls from the knife like soft butter, it is ready to use.

When priming with a putty knife [or wedge tool], begin by placing a portion of the oil painting ground or primer in the center of the [already sized] panel. Spread it in one direction, and then in the opposite, and finally in a diagonal direction. Clean the putty knife and run it over the ground to smooth and even out the surface. Also, prime the edges of the panel and the cradles if applicable. Don’t forget to apply GAC100 on the cradle edges first if priming them for painting. 

When the first coat of oil painting ground is completely dry (about 7 hours), lightly sand the surface with a sanding block using light grade 400/grit sandpaper. A second coat can be applied the next day or any time after the first coat is dry. If using basswood, for each additional coat to the panel face, apply the same number of applications to the panel back.

If priming with a brush, use a large bristle brush, at least 2″-3″ wide (proportionate to the size panel you are using), and apply the ground or primer with quick alternating strokes, working it well into the surface. After evenly distributing the ground or primer over the entire surface, finish by going over it lightly with a clean brush, carefully in straight lines, or use a short-nap [cotton] roller. Let the first coat dry, then sand and apply a second coat. At least two coats of ground or primer should be applied. The more coats of ground or primer that are applied, the smoother the surface will become. For basswood panels, follow the same instructions, but also prime the back. For each additional coat to the panel face, apply the same number of applications to the panel back

Step 4 – To Finish
Eliminate any unevenness on the finished primed surface by lightly sanding the panel after it has thoroughly dried. The finished primed panels should be allowed to dry completely at room temperature before painting. If you prepare several panels at a time, then you will have stock on hand that is dry and ready to paint when needed. 

Below is a video produced by Gamblin with Scott Gellatly, technical director, explaining how to prime a painting.



All things Ampersand,
Karyn Meyer-Berthel
Artist & Social Media Specialist
Ampersand Art Supply

Click here to explore the full selection of Ampersand panels and tools.

Painting on Panel: Sizing

All wood panels must be sized, or sealed, before painting to contain the natural chemicals within the wood that can break a painting down over time. Support Induced Discoloration (SID) occurs when a panel is not properly prepared and these chemicals leach through to the paint on the surface. By choosing a denser panel with a low acid content, an artist greatly reduces their risk of SID. However, all wood panels should be sized (sealed) and primed before painting to ensure their longevity.
Traditionally, panels were sized (sealed) with hide skin glue before applying the Gesso grounds. However, current research has shown that hide glues like rabbit skin glue do not completely seal the surface, and deteriorate over time. Conservators consider a PVA size or acrylic resin a superior modern substitute for hide skin glue. If you are sealing your own panel such as Ampersand’s Hardbord™, we recommend using GAC100 from Golden®. This is a superior sealer for panels. Its high resin content seals the panel very well and forms a good film on the surface. GAC100 also forms a good foundation for proper adhesion to layers of gesso. With Ampersand’s coated surfaces such as Claybord and Gessobord, Ampersand uses their Archiva-Seal technology to seal their panels prior to applying their painting grounds. This technology employs a specialized method to apply their proprietary sealers so that the actual fibers of the board are sealed. This sealing process creates a barrier between Ampersand’s acid-free coatings and the hardboard surface, ensuring that an artists’ work will be protected over time.
Prior to sealing, make sure your panel is clean of any dust or debris. Some experts recommend that you slightly sand the surface of the panel to ensure good adhesion. Note that Ampersand Hardbord should not be sanded. Removing the top layer of tempered fibers can cause the panel to warp when gesso is applied. Next, apply GAC100 liberally with a brush onto the panel. Take a putty knife or spatula and work the GAC100 into the fibers of the panel while it is still wet. Smooth it out and let this first layer dry. Next, apply two additional coatings with a brush, letting each layer dry in between coatings (no need to sand between layers). Make sure that the sealer is evenly distributed throughout the surface. It is highly recommended that you seal both sides of the panel to retard moisture penetration on the front and back and to equalize both sides of the panel to prevent warping.

All things Ampersand, 
Karyn Meyer-Berthel 
Artist & Social Media Specialist 
Ampersand Art Supply 

Click here to explore the full selection of Ampersand panels and tools.

Painting on Panel: Cradling and Supports

Cradled panels in the warehouse

In order to give a panel extra support, many artists produce a bracing system (cradling) for their panels. While this is not an option for solid wood panels due to their expansion and contraction over time, manufactured panels are structurally sound enough to be cradled. For panels over 24″ cradling is advised. 

Elaine and Veronica inspecting panels


Cradles are generally a separate unit the size of the panel that is attached to the back using carpenters glue and C-clamps. Larger size cradles will generally have cross-braces, much like stretcher bars for canvas. When choosing a wood for your cradle, it’s best to go with high quality multi-ply plywood, as this will give you the best protection against warping. Solid woods are to be avoided, as they have a uniform grain that will warp over time in a thin strip. Do not nail or screw the cradle onto the panel, or you will have a blemished surface that is certain to deteriorate over time. 

Save yourself the trouble of all this carpentry work by using an Ampersand cradled panel. Only Ampersand builds their cradles by hand with premium grade 13-ply birch plywood for maximum stability and a clean, finished look from edge to edge. Choose from 3/4″, 1.5″ and 2″ Deep, all carefully made by hand in Buda, Texas. 
Ampersand Claybord and Gessobord panels are now available in a new 1.5″ Cradle Profile that offers you more flexibility for hanging and framing your work. Featuring a 1.5″ total depth, this new cradle profile is handcrafted with premium grade 13-ply birch plywood, designed to fit both standard canvas and floater frames. The cradle can easily be painted or stained to complement the artwork or primed with gesso to wrap the image around the edges.

For ideas on how to treat the edges of the cradle, consult this article on hanging and framing.

All things Ampersand, 
Karyn Meyer-Berthel 
Artist & Social Media Specialist 
Ampersand Art Supply 

Click here to explore the full selection of Ampersand panels and tools.