In the early 2000's we pioneered the current Koa grading system specifically for the instrument market which we adopted from the tonewood Maple, Spruce and Cedar market. Much mahalo and a big thank you to David Lapeyrouse of Timbre Tonewood in BC, Canada for all your help in those early years! Previous to that, Koa sets were often sold as "A", "AA" or "AAA" according to the models of guitars in the market especially at Taylor Guitars.
Yet, with so many different customers with specific needs and the boom of the ukulele industry, we needed more grades to fit the market, so we adopted the 1A thru 5A grade. Even now, 20+ years later, we continue to hone the grading and have been knows to offer 4A+, 5A and the ever-so-rare 5A+ aka 6A or as we have recently started calling them "Ubers"!
We use the grading system explained below for our Koa tonewood products namely Koa ukulele sets, Koa acoustic guitar sets and Koa electric guitar sets.