When you consider all the newer synthetic alkyds and urethanes on the market now, I shake my head primarily because, if we look back at historical archival restorations of Flemish and Italian oil paintings, there are time-proven flexible finishes. These finishes are combinations of amber-infused walnut and linseed oils. These mediums have lasted for centuries with incredible clarity and resilience against temperature, dirt, and grime. As a fine art educator and oil painter, I can confidently say that these amber-infused combinations produce the finest finishes on any bamboo fly rod.  I can smell fly rods with straight urethane finishes, and these finishes lack any physical data demonstrating archival properties. Not only do Italian oil painters use amber infused varnishing techniques, but musical instruments that are over 500 years old still glisten using walnut oils and linseed oils that mingle effortlessly with amber. The result is an incredibly long-lasting, flexible, glowing fi...