Would any decent quality (established brand) gloss acrylic medium seal a wood panel effectively?
There is a lot of advice online about sealing wooden panels with a gloss acrylic medium. The majority of the advice recommends using Golden gloss acrylic medium (or their GAC though Golden now say their medium is better for this job) though others refer to using any gloss acrylic medium. There are a number of good quality gloss acrylic mediums marketed for professional use though coming under the ‘midrange’ umbrella as well as excellent quality versions under the ‘artist grade’ umbrella. As far as I’m aware, Golden only produce ‘artist grade’ products. Considering the multiple coats and hidden nature of the sealing layers, it would be helpful to know what is suitable.
Thanks.
Thank you for these details and the video link. From the Golden information it appears any issues would show quickly (within 48 hours) and it’s interesting the video comments SID shouldn’t be a concern for most artists, primarily those working in light colours / thin layers. My concern was more SID based (even though I work in dark and thick layers of acrylic paint) as a lot of online info says you always HAVE to seal wooden panels BUT it also appears most of the online info refers directly to the information from Golden, though omitting that it’s not always necessary. I also notice lots of online info says you have to seal the back of panels and supports with gloss medium too (Golden largely recommended) but Golden actually warn against this due to the tacky surface of the artists’ gloss medium. Thanks again for the helpful information.
Isn’t acrylic porous, even glossy acrylic medium that is high in acrylic solids?
I assume that it’s important to have something to combat that porosity if trying to seal something.
It depends what you would like to use this glossy medium for, to reduce absorbency or to block SID?
If you would like to block Support Induced Discoloration (SID) from your acrylic painting, then we recommend either GAC 100 or Gloss Medium. 1-2 coats of each. These are the only 2 mediums we make at GOLDEN that can perform in this way. There may be other brands products that also block SID, but we have not teted for that. It is mostly an issue when working over dark MDF or some other wood products that have higher concentration of water soluble colorants in the fibers, and with thicker applied or slower drying acrylics. SID is only a concern with waterborne painting media such as acrylics, as it requires the water to activate the colorants and then the evaporation of the water to draw the colorants from the wood into the paint layers. SID does not affect oil paints. Here is a video about SID: https://www.goldenpaints.com/videos/support-induced-discoloration–sid—what-is-it–and-how-to-minimize-it
If you are not concerned with SID, and only want to reduce absorbency of the panel to paint in acrylics , then most glossy mediums will do from any brand. You can apply the glossy medium to the surface of the wood, then acrylic dispersion ground (acrylic Gesso) over that. If your surface is still too absorbent, then you can apply more glossy medium before the acrylic colors if you like.
If you are preparing your panel for oils, then GOLDEN does not recommend any glossy product be applied to the surface or in any layers of the preparation. Rather we simply recommend using several coats of acrylic dispersion ground to prepare the surface. Here is an article that discusses some recent finding about using Oils over glossy acrylics: https://justpaint.org/revising-our-recommendations-for-using-oils-over-acrylics/
Thanks,
Greg
Yes, water-based acrylics, including gloss mediums, have a relatively high water permeability. Products from hardware stores, which are intended for sealing wood in exterior setting, should provide better protection. Here are some options, if you want to explore this further: https://justpaint.org/de/preparing-panels-for-a-life-outdoors-2/
For fine art purposes, where the panel paintings are kept in ambient conditions, it shouldn’t be necessary to seal the reverse of wood panels.