Polyvinyl alcohol also has good uses in coatings. The polyvinyl alcohol aqueous solution is condensed with formaldehyde under the catalysis of hydrochloric acid to form a water-resistant polyvinyl formal polymer compound, which is widely used as interior and exterior wall coatings, whitewashing, and caulking of buildings. Polyvinyl alcohol paint has good weather resistance, water resistance, does not swell when exposed to water, does not embrittle, is non-toxic, tasteless, and has the advantages of low price.