A lacquer comprising a homogeneous or heterogeneous dispersion of a linear polyester in a solution of a film-forming polymer in a liquid. Useful linear polyesters are polymers of ethylene terephthalate, ethylene isophthalate, ethylene orthophthalate, propylene terephthalate, propylene isophthalate, propylene orthophthalate and copolymers of two or more of these. Especially suitable film-forming polymers for use with the invention are copolyesters of ethylene glycol, terephthalic acid and isophthalic acid. Particularly suitable liquids for use with the invention are ethylene carbonate and propylene carbonate. In preference in the lacquer the proportion by weight of linear polyester is in the range 2 percent to 30 percent, but preferably in the range 5 percent to 20 percent, of the total weight of linear polyester plus film-forming polymer in the lacquer. In a preferred lacquer the proportion by weight of linear polyester plus film-forming polymer based on the total weight of lacquer is in the range 5 percent to 35 percent, but is more preferably in the range 10 percent to 20 percent.