Compositions for use in the manufacture of three-dimensional objects including compositions for use as a support and/or release material in the manufacture of the three-dimensional objects are provided. There is thus provided, in accordance with an embodiment of the present invention, a composition suitable for building a three-dimensional object. The compositions may include, inter alia, a curable component, having a functional group, wherein if the functional group is a polymerizable reactive functional group, then the functional group is a (meth)acrylic functional group, a photo-initiator, a surface-active agent and a stabilizer; wherein said composition has a first viscosity of about 50 500 cps at a first temperature, wherein said first temperature is ambient temperature, and a second viscosity lower than 20 cps at a second temperature wherein said second temperature is higher than said first temperature, wherein, after curing, the composition results in a solid form. There is thus provided, in accordance with another embodiment of the present invention, a composition suitable for support in building a three-dimensional object. The compositions may include, inter alia: a non-curable component, a curable component, wherein the non-curable component is not reactive with said curable component, a surface-active agent and a stabilizer; wherein said composition has a first viscosity of about 20 500 cps at a first temperature, wherein said first temperature is ambient temperature, and a second viscosity lower than 20 cps at a second temperature wherein said second temperature is higher than said first temperature, wherein, after irradiation, the composition results in a solid, a semi-solid or liquid material. A method for the preparation of a three-dimensional object by three-dimensional printing is provided in accordance with embodiments of the present invention. Embodiments of the present invention further provide a three-dimensional object prepared according to the methods of the invention.