they are not really all that difficult to make.Two lots of contrasting pieces of wood one -say .250 wide another .75'' wide, cut to width required and glued together. i make mine about 1'' thick which allows about 4 strips when ripped length ways on the glued up blocks. Trimmed up on my lam grinder and then I back each strip when cut to required thickness with core-tuff glass but phenolic can also be used.