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All Things Ampersand

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: 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.

Featured Artist: Valerie Allen

Valerie’s photo entry in our contest

We held our first photo contest on Facebook this spring asking for artists to submit shots of their studio with their Ampersand panels in clear view.  Out of the entries, we selected three winners to share with you in our blog.  Over the coming months, you’ll get to know those artists and their Ampersand studios a bit better.

Athena’s Timeline:  The Prelude, Mixed Media on Claybord
Detail of Athena’s Timeline Illuminated

Michigan artist, Valerie Allen, has always known she was an artist.  She was the go-to person in high school for anything art, always working on projects and commitments.  “I remember begging my dad to drive me to an art contest 2 hours away — definitely a long shot — he missed his favorite grouse hunting day.  Lucky for me– my persistence paid off with me winning the grand prize.  He always remembered that day with a smile.  The country girl showing the city folks a thing or two about design!”  Her persistence as an artist has continued to pay off, as she is an award winning exhibitor and instructor.  As an educator for many universities throughout her career and ongoing with the Alden B. Dow Museum of Science and Art and the Golden working Artist program, Valerie has  a lot to share with her students about good materials.  

Valerie has always been attracted to a range of mediums.  She found that her love of art history and process enlightened her on the range of mediums and the artists that used them.  Naturally her experimentation followed the artists that attracted her:  Van Gogh, Picasso, Rauschenberg, moving through oils, ceramics, lithography and encaustic.  With her move into the Golden Working Artist’s Program, Valerie has concentrated on encaustic and acrylic, both which do quite well on Ampersand panels.

Valerie came to find Ampersand Claybord™ through a colleague and artist, Armin Mersmann.  He hired her for instruction at the Alden B. Down Museum of Science and Art.  A lovely bonus came from their working relationship as Valerie and Armin have been married now for ten years.  

“I find Ampersand to be such a versatile support for my work.  I use it for my acrylics that are layered with thick gels and pastels.  I also use it to mount my encaustic monotypes.  I really appreciate the archival qualities of the boards.  When I sell artwork on Ampersand, I know with confidence it will stand the test of time in any setting,” Valerie explains.  

To see more of Valerie’s work or her schedule for the Golden Working Artist Program, check out her website:  valerieallen.artroof.com

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.

Panel Painting Tips: How to Seal Hardbord Panels

 

Hardbord™ is one of the few panels we offer unprimed and unsealed as a raw wood surface. There can be great pleasure in working directly on raw wood. However, for long term stability, we recommend sealing all unprimed wood panels, including our own, to protect against support induced discoloration (SID), warping and adhesion issues. Whether you’re working in acrylics, oils, encaustics, alkyds or tempera, paint will adhere best to surfaces that have been properly prepared using archival practices.
 

 

A size is a thin solution (often a weak glue) that is brushed directly onto a support. Sizing or sealing is recommended to protect Ampersand’s uncoated panels from support-induced discoloration (SID) when using  acrylic gesso. If wood is not sized or sealed properly before applying the gesso, yellowing can occur because water [a solvent] can cause acids, occurring naturally in wood, to migrate to the surface. In fact, it is extremely important  to properly seal any and all un-primed wood substrates to prevent support-induced discoloration (SID) 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 it still needs to be sized and sealed. Sealing only the “paintable” side will possibly lead to warping if moisture or pollutants leach through the raw wood cradles or backing. So, seal the entire panel for the ultimate protection.  

To see first hand the effects of SID on a panel, check out this video from Golden:

 


To apply the size, use a wide flat brush to lay on 2 layers of GAC 100 or 4 layers of Gamblin PVA size, allowing each to dry completely before applying gesso layers. For more complete directions click here to read about sealing with Acrylic Gesso and click here to read about sealing with Oil Ground.


Some artists prefer having this work done for them, and by all means, feel free to purchase a Gessobord™, Aquabord™, Claybord™, Encausticbord or Pastelbord™ to suit your purposes.  Gessobord and Claybord, along with Hardbord, Encausticbord and the Artist Panel are all on sale right now through the end of September.  Find a retailer near you:  Fall Sale

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.

Sealing and Varnishing Art Work on Ampersand Panels

Sealing and varnishing finished artwork on Ampersand panels is extremely important especially when framing without glass. Be sure to select a varnish that is appropriate to the type of paint you are using. Provided below are a few basic suggestions for sealing and varnishing several popular mediums using products we have successfully tried and tested on our panels.

Watercolors & Gouache


Seal watercolors or gouache with several light coats of spray varnish (or fixative), being careful to spray outdoors during warmer months or in a well ventilated and heated area during colder times of the year. We recommend the Krylon® UV Archival varnishes.These spray varnishes offer advanced non-yellowing protection against fading, dirt, moisture and discoloration. The Krylon® UV Archival varnishes contain superior levels of UV light absorbers and are removable for conservation purposes. For additional protection against scratches during transport and also ultraviolet light, follow the application of Krylon® spray varnish with Golden® MSA UVLS or Golden® Polymer UVLS varnish. About 4 coats brushed-on, provides a very durable archival finish and is also removable for conservation purposes.
Oils


 

Ampersand panels do not lessen the drying time required for oil paints before varnishing. Allow the oil painting to dry for 3-6 months before applying the varnish. A good choice is Gamblin’s Gamvar that is easily applied using a soft natural hair brush. Unlike varnishes made from natural resins like Damar and mastic, Gamvar does not yellow with age or become more difficult to remove. It contains a UV stabilizer and offers some measure of protection to less lightfast pigments, depending on how heavily it is applied. For tips on application, Gamblin offers this video demonstration.

Acrylics

For Acrylic paintings, a light coat of an acrylic varnish like Golden® MSA UVLS or Golden® Polymer UVLS varnish is advised. Problems such as smoke damage, handling blemishes and dust or dirt accumulation on the surface of the painting can be removed along with either varnish type. Golden® varnishes offer protection from UltraViolet (UV) rays generated from the sun and consolidate the artwork with an even sheen. Gloss varnishes can intensify colors while Matte or Satin Varnishes soften the color and minimize glare. Alternatively, Gamblin’s Gamvar [see varnishing oils] can effectively be used to varnish acrylic paintings.  

This is a Golden video on the Proper Spray Application of MSA varnish
Pastels

Sealing pastels with spray fixative tends to dull the color of the pigments, so we recommend all pastels be framed under glass. The glass protects the fragile nature of the pastels while also keeping their colors true to life. For tips on matting and framing pastels, consult this article.
Sealing Scratchbord™ (formerly Claybord Black)

Seal finished Scratchbord™ art with a spray fixative like Krylon® UV Resistant Clear Coating  or use the Krylon® UV Archival Spray Varnish. The fixative [or spray varnish] will dissolve fingerprints or smudges and will protect the surface from dirt and moisture. For best results, first remove all loose dust and debris from the surface with a soft brush. Then, spray with 2 – 3 coats [as directed on can] in a warm, well ventilated environment during low humidity.