A method of preparing a spinal rod includes obtaining a body that is elongate along a central rod axis and includes a proximal end and a distal end spaced from each other along a longitudinal direction to as to define the spinal rod. The body defines an outer surface extending between the proximal and distal ends and the body comprises a material that is malleable so as to allow the spinal rod to be bent to a predetermined curvature. The method includes producing at least one longitudinal line on the outer surface, such that the at least one longitudinal line is elongate along the longitudinal direction and parallel with the central rod axis. The method also includes producing a plurality of harsh marks incrementally spaced along the outer surface and producing reference numbers on the outer surface. Each of the reference numbers identifies a distance along the longitudinal direction from the proximal end of the body to a respective one of the hash marks.