Abstract: A mold construction system is presented for use in additive manufacturing of a metal object. The system comprises: at least one mold provision device controllably operable to form one or more mold regions defining one or more respective object regions in a production layer, and configured to receive molten metal deposited to each object region; and a control system operating said at least one mold provision device in accordance with a predetermined building plan. The mold provision device is controllably operable, in accordance with said predetermined building plan, to create each mold region, in each production layer, with one or more metal-facing zones and one or more metal-nonadjacent zones around the metal-facing zone. Each metal-facing zone is configured to define a cavity forming the object region to receive the molten metal therein, and is configured with higher compressibility relatively to at least a sub-zone of the metal-nonadjacent zone.