A plastron is a chest covering which sits over a lower layer. The same term is used to describe a fencer’s chest pad, an armored breastplate, and a tortoise’s belly. The Plastron shirt is cut with large pleats set under the armholes, forming a pseudoplastron across the chest.

The pleats add volume into the skirt of the garment, which is cut without side seams, so that the tails hang freely without weight or stiffness. A single chest pocket on the left and full tailored cuff plackets behind the wrist refer to more traditional shirt making. Buttons are real shell interpretations of a standard cats eye button, and the whole garment is sewn with cotton thread.