Abstract: The invention relates to a container (1?) made of a thermoplastic material, especially PET, having a body (2?) which, for at least a part of its height, is substantially prismatic in shape with a substantially triangular cross section and with three faces (6) joined by three edges (7), each of which is shaped in the form of a groove (8) which opens outwards and which has a rear wall (9) having a reversed curvature with its convexity being directed outwards.

Abstract: The invention relates to a vessel (1), mainly a bottle, of a thermoplastic material made by blowing or stretching-blowing a heated perform, the vessel comprising a bottom (2) and a neck (3) connected to a body (4), characterised in that the body (4) includes an axially central portion (5) surrounded by an axially lower portion (6) and an axially upper portion (7) defining a connection area respectively with the bottom (2) and the neck (3), the axially central portion (5) being essentially rigid while the axially upper and lower potions (6, 7) can be essentially deformed and a have shape-memory characteristics so that they can recover their initial shape under the hydrostatic pressure of the liquid content.