A formulation usable in additive manufacturing of a three-dimensional object is provided. The formulation comprises one or more monofunctional curable material(s); one or more hydrophilic multifunctional curable material(s); and one or more water-miscible non-curable material(s), such that a total amount of the curable materials is 20% or less, by weight, and a weight ratio of a total weight of the monofunctional curable material(s) and a total weight of the hydrophilic multifunctional curable material(s) ranges from 1:1 to 10:1. The formulation features, when hardened, properties of a weak and flowable gel. Additive manufacturing processes utilizing the formulation as a support material formulation are also provided.