Liner blocks have various names, among them
are,peones,contraaros,linings,glue blocks etc. Their purpose is to give
added glueing surface to the sides.They must have enough surface to allow
for the removal of wood for the banding and still support the top and back.
Pine,spruce,mahogany etc. are used for liners.A light wood is prefered as
heavy woods add excess weight to the guitar.