All the finest pianos have premium solid-spruce soundboards, but spruce soundboards are not created equal. A premium soundboard will be made of straight-grain solid spruce (not laminated) with a minimum of 8 grains per inch and be free of knots and irregularities. These qualities ensure overall structural integrity and even distribution of vibrations. Most manufacturers do not specify anything beyond solid vs. laminated, allowing for a wide variance in wood quality.