Abstract: Soft material design methods for developing protective panels against a hail with a diameter of more than 25 mm are provided, wherein the protective panel comprises a soft material layer. The methods comprise: selecting a material for the soft material layer, wherein the material has a Young's modulus Esm in a range of 1 MPa to 150 MPa, preferably 5 MPa to 100 MPa; and determining a minimum thickness Tsm of the soft material layer based on the size of a hail and the material properties of the soft material and other materials inside the protective panel. A protection system that includes these protective panels covers a whole vehicle or some fragile parts on the ground.