Apparatus and methods of decorating guitars and other stringed musical instruments are disclosed. In one aspect, an apparatus may include a carrier to hold a portion of a guitar, a surface to support the carrier, one or more ink-jet printheads to apply radiation-sensitive ink compositions on a surface of the portion of the guitar, when the portion of the guitar is held by the carrier, and when the carrier is supported by the surface, and a radiation source to supply radiation to the radiation-sensitive ink on the surface of the portion of the guitar. In another aspect, a method may include providing at least a portion of a guitar having a surface, and applying a decoration over the surface by spraying radiation-sensitive ink compositions over the surface with one or more ink-jet spray nozzles and exposing the radiation-sensitive ink compositions to radiation.