Heater shield, gules

Here the flanks are arcs whose radius is the full width of the shield, each swung from the foot of the opposite side, so the point is the apex of a vesica. Red is shown by vertical strokes, a code first engraved at Leuven in 1600 and made standard by Silvester Petra Sancta in 1638. No medieval canon of shield proportions survives; the length of the sides is a choice.