The hydrophobic material is selected from the group consisting of (i) an acrylic polymer such as copolymers of acrylic and methacrylic acid; (ii) an alkylcellulose such as ethylcellulose; (iii) other commonly used retardant coatings such as shellac, zein, and hydrophobic wax or waxy-type products either alone or in admixture with fatty (aliphatic) alcohols (e.g., cetostearyl alcohol), hydrogenated