Composition and method for additive manufacturing of an object

A method of additive manufacturing of a three-dimensional object, the method comprising sequentially forming a plurality of layers in a configured pattern corresponding to the shape of the object, thereby forming the object,

• wherein said formation of each layer comprises dispensing at least one uncured building material, and exposing the dispensed building material to curing energy to thereby form a cured modeling material, and wherein said uncured building material comprises an uncured modeling formulation, an uncured modeling formulation comprising:
• at least one hydrophilic mono-functional UV-curable material;
• at least one hydrophilic multi-functional UV-curable material;
• at least one non-hydrophilic mono-functional UV-curable material;
• and
• at least one non-hydrophilic multi-functional UV-curable material;
• wherein:
• a total concentration of said hydrophilic UV-curable materials is at least 50 weight percent of the total weight of said uncured modeling formulation;
• and
• a total concentration of said non-hydrophilic UV-curable materials is no more than 50 weight percent of the total weight of said uncured modeling formulation,
• and wherein the formulation forms upon curing, a material characterized by an impact resistance higher than 20 KJ/m and by a water absorption of at least 5%.

The three-dimensional object of claim 38, wherein at least a part of the object is characterized by:

• a water absorbance of at least 5%:
• HDT higher than 40° C.;
• and
• an impact resistance higher than 20 J/m.