Coating method for forming flame retardant substrate

A method includes coating a substrate to provide a flame resistant substrate. In an embodiment, the method includes preparing an aqueous solution. The aqueous solution comprises a phosphate material, a cationic material, and a water. The method further includes exposing the substrate to the aqueous solution to produce a coating on the substrate. The coating includes the cationic material and the phosphate material. The method also includes exposing the coating on the substrate to a melamine solution.U