[1][2] The line is typically darker than the rest of the shaft skin, even though its shape and pigmentation may vary greatly among males.

[5][6] The line consists of a subcutaneous fibrous plate, which may vary in prominence and thickness in various areas of the genitals.

[7] In the scrotum, the line is located over the internal scrotal septum that divides the two sides of the sac and is densely occupied by nerve fibers.

[8] The raphe may become more prominent and darker when the scrotal sac tightens due to contractions.

The raphe results as a manifestation of the fusion of the labioscrotal, urogenital and preputial folds during the embryonic development of the male fetus.