I work only with air dried woods that I have harvested for their unique figured grain characteristic. These woods will always move with changes in humidity., unlike kiln dried lumber whose moisture content has been reduced to 6%. I am no pleased with modern commercial synthetic varnishes that have a plastic look. I have read much on the subject of classical oil and alcohol varnishes utilizing tree resin. I don’t want to move forward without some advise from persons with experience in making such varnishes. Given that each resin has different acid resin constituents and percentages developing a receipt by trial and error could be a life long expensive process. I have purchased a wide assortment of gums and resin based upon my readings but I am not applying this custom finish to canvas.
I’m not sure if this is information you already have but this site has some traditional recipes for wooden finishes: Http://www.woodfinishingenterprises.com/techinfo.html, but it seems that you need to buy the author’s book to get all of the instructions.
Scott Rowley
To be honest, I am not sure what you are asking here. Are you looking for a recommendation for an alcohol soluble natural resin varnish or an oleoresinous varnish? More importantly, is it for woodwork or for a painted work of art? This may seem a spurious distinction but the slight yellowing of a woodwork surface coating may or may not be considered offensive, while it is generally best avoided in pictorial surface coatings. More importantly, reversibility of said coating is vastly different if applied over a wood surface as compared to a fragile pigmented surface. I am sure that my furniture conservation colleagues will be able to find numerous examples that defy my oversimplified dichotomy above; the point is still generally valid.
Alcohol varnishes are fine for some media, like aqueous works, but very problematic for oil paintings, etc. Is it an oil varnish you desire. If so I hope it is for wood as we cannot recommend such varnishes as surface coatings for pictorial works. The types of resins you describe can seem very romantic; especially if they have a seemingly long history of use (even this can be misleading. Many believe that Dammar was used by the Old Masters, but there is no mention of it before the 19th century).
In short, we need a bit more information before we can really comment in a meaningful manner.
