From Mother Goose: The voicing tray was designed for use in shaping hammers, both upright and grand. The tray comes with a hammer spacing bar with lines etched and colored. [Note: clips no longer available for travel bar.] In using the tray in an upright, the tray’s channel is placed under the back of the hammer with the tray under the hammer shanks. The spacer should be used in the channel if there is a gap under the hammer tail. The placement of the tray in a grand is with the channel over the catchers, with the hammer tails resting in front of the channel. The spacer is not used with the tray in grands. The tray may also be used to install upright hammers keeping the glue from running onto the hammer felt rail. The spacer bar’s lines are used to travel hammer shanks. When the bar is raised free, the shanks move against the etched lines on the bar. The shanks that need to be traveled can then be identified. The bar can also be used to travel grand damper levers.