tools for voicing the crown of hammers, either directly in the string grooves to take away some of the harshness of attack (a good technique for maintaining the voice of a set of hammers as they are used), or voicing between the grooves for una corda tone quality. In the array of tools with numbers, the numbers refer to needle numbers, 12 being the smallest. Available as quilting needles at sewing supply stores. I tend to use only 10 and 12, and the ones that are spaced farthest apart (the array photographed was early in experiments).