Adjustment of the neck base to make a tap on the underside of the Scroll match the Back Plate tap tone...
			...The general rule is that if the (bottom of the) Scroll tap is lower than the (center of the ) back plate tap tone, then the side of the neck base should be scraped to a more concave shape, removing material evenly from both sides. ...If, however, the scroll tap tone is higher than the back plate tap tone, then scraping material from the root of the neck will lower the tone of the scroll tap until it matches the back tap tone. ...The sides of the base of the neck should be shaped initially so that the side of the neck shape continues into the neck base area so that the players thumb does not feel any shape change as he slides into the upper positions. This naturally produces a convex shape to the side of the neck root..