Abstract: A process for the production of an air-drying, modified amino-resin, which process comprises co-polycondensing one or more dialkyl ether compounds, which are dialkyl ether of the dimethylol derivatives of compounds containing two primary amido groups or similar groups, with at least one compound containing an auto-oxidative group, or polycondensing the said one or more dialkyl ether compounds and reacting the compound containing an auto-oxidative group with the condensate; the alcohol released being removed from the mixture. The auto-oxidative groups are typically supplied by allyl ethers and the dialkyl ether compound is e.g. bismethoxymethylene urea. The modified resins rapidly form hard films when exposed to atmospheric oxygen in the presence of drying agents.