The growth of 3D printer inks is in line with the growth of 3D printing technology. Finding a suitable formulation of 3D printer ink is crucial for fulfilling the demands of construction fields, bio-printing, and consumer products. Soft materials, such as silicone paste, have become one of the requested inks owing to their natural characteristics, cost effectiveness, and substantial environmental friendliness. However, because of the thixotropic behavior of silicone, the development of silicone paste as a 3D printer ink is challenging. This study aimed to develop a new soft material formulation ink made from silicone for extrusion-based 3D printing. A common silicone polymer was added with 0.2% wt of Thi-Vex and sericite mica ranging from 2 to 10% wt. The extrudability and viscosity of the silicone ink were tested by extrusion line printing. A uniaxial tensile test was conducted to evaluate the tensile strength and elongation percentage. The feasible formulation was found to be 3:1:0.2% wt:2% wt (Silicone part A, part B, Thi-Vex, sericite mica) with the tensile strength of 1.37 MPa and 148.71% of the percentage of elongation before the break.