a) adding a pH regulating agent to a first solvent;

b) adding thermoplastic starch to a solution of a);

c) heating the solution of b);

d) adding a viscosity stabilizing agent to the heated solution of c) for their reaction;

e) cooling the solution of d);

f) adding a second solvent to the cooled solution;

g) adding a natural resin which is shellac to the solution of f);

h) stirring the solution of g) and retrieving a final solution,

wherein the composition comprises 7 to 25 weight % of the thermoplastic starch, 1 to 5 weight % of the pH regulating agent, 0.1 to 0.5 weight % of the viscosity stabilizing agent, 3 to 10 weight % of the second solvent, 15 to 30 weight % of the shellac, and the remainder being the first solvent.