Municipal blue, and the reason it exists is colour separation. A pile of identical black sacks reads as one mass; a single blue one among them gives the eye somewhere to land and implies a system — somebody, at some point, was sorting rubbish here. The material is the interesting part: this sack is translucent rather than opaque, so the shading has to carry light through the film and pick up the shape of whatever is inside without a subsurface setup. That is handled in the base colour and roughness together, tuned to hold at both handheld distance and across a street. Creased volume rather than a smooth bag, with the folds concentrated where the plastic is under tension. At 1,108 triangles it is the lightest model in the vault, which makes it the cheapest way to break up a repeated silhouette.