Latices of vinyl acetate polymers

A latex of vinyl acetate polymer comprising:

• particles of a vinyl acetate polymer, said polymer being selected from the group consisting of at least one homopolymer of vinyl acetate and at least one copolymer of vinyl acetate with at least one other copolymerizable monomer selected from the group consisting of vinyl esters of branched or unbranched, saturated monocarboxylic acids (C.sub.1 -C.sub.12), and alkyl (C.sub.1 -C.sub.10) esters of unsaturated monocarboxylic or dicarboxylic acids (C.sub.3 -C.sub.6), said polymer having a glass transition temperature between -20.degree. and 50.degree. C., and said particles having an average diameter between 0.05 and 1 .mu.m and being present in said latex at a concentration of between 10 and 70% by weight;
• and
• a protective colloid consisting essentially of:
• a water-soluble polymer (a) containing at least one monomer selected from the group consisting of N-methylolacrylamide and N-methylolmethacrylamide and
• a water-soluble polymer (b) of ethylene glycol, said polymer (b) having a molecular weight between 1,000 and 50,000,
• said latex having a first viscosity at acid pH, said first viscosity being lower than a second viscosity obtained when the pH of said latex is made alkaline and wherein said second viscosity remains invariable irrespective of subsequent change in the pH of the latex.