A breast prosthesis for wearing against a chest of a user includes a bag, a first silicone rubber and a silicone agglomerate putty. The bag includes at least three films that are sealed together around a periphery so as to define at least a front chamber and a back chamber. The first silicone rubber is disposed in the front chamber and is cured in an outer shape of a breast. The silicone agglomerate putty is disposed in the back chamber and is configured as a shear thinning fluid that conforms in shape to surface features of the chest of the user when placed against the chest of the user.