perçage en serpentin

CONT: Les perçages en arcs, en zigzag, en serpentin et en dents de scie, que la désignation suffit à expliquer [...] donnent à certains timbres un aspect spectaculaire [...]

OBS: percé en serpentin; serpentine roulette: The cuts form a serpentine of wavy lines.
OBS: serpentine roulette: This roulette is made on a machine with curved cutters alternately faced opposite so that the finished roulette is a sinuous or undulating line.
OBS: ... it [rouletting] is further differentiated by the pattern of the cutting: serpentine, scalloped (or ""en arcs""), saw-toothed (or ""en scie""), straight-line (or ""en ligne""), etc.