Alkyd resins are obtained by reacting (a) polymers of allyl type esters, (b) polymers of allyl type acetals, or (c) polyallyl type alcohols obtained from said esters or acetals by hydrolysis or alcoholysis, with a polycarboxylic acid or an anhydride, chloride or ester of a polycarboxylic acid. Polycarboxylic acids specified are malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, maleic, fumaric, itaconic, citraconic, malic, tartronic, phthalic, isophthalic, terephthalic, 1,8-naphthalic, citric, aconitic and tricarballylic acids. These may be mixed with monocarboxylic acids, e.g. acetic, propionic, butyric, acrylic, methacrylic or crotonic acid. There may also be present other polyhydric alcohols, e.g. ethylene-, diethylene-, triethylene-, propylene- or butyleneglycols, glycerol, di-, tri- or penta-glycerol, pentaerythritol, dipentaerythritol, 2-(hydroxymethyl) - propen - 1 - ol - 3, 2 - (hydroxymethyl) - buten - 1 - ol - 3, 2 - (1 - hydroxyethyl)-buten - 1 - ol-3, or monohydric alcohols, e.g. methyl, ethyl, propyl, allyl, methallyl and crotyl alcohols. The alcohols and acids may be reacted in equimolecular proportions or ratios of from 1 : 10 to 10 : 1 may be employed. The reaction is effected by heating from 80-200 DEG C. with or without actinic action and takes place in three stages which may be effected separately or successively. The products of the first two stages are largely chain-type esters containing a plurality of ester linkages in the molecule. The final stage is probably principally one of cross-linking which may or may not involve esterification. The reaction may be effected in closed stirring vessels under a blanket of inert gas, e.g. nitrogen and in the presence of solvents, e.g. benzene, toluene, xylene, chloroform, carbon tetrachloride, ethylene dichloride, propylene dichloride, ethylene trichloride, propylene trichloride, the butylene chlorides, cresols, cyclohexanone or methylcyclohexanone. Specified catalysts for the reaction are oxygen; sulphur; finely divided iron and zinc; zinc oxide; magnesium oxide; calcium oxide; peroxides such as benzoyl peroxide, acetyl peroxide, tertiary butyl hydroperoxide, phthalic peroxide; cobalt, lead and manganese linoleates or naphthenates; or aluminium chloride, stannic chloride or boron trifluoride. The amount of catalyst used may be within from 0.1 per cent to about 5 per cent by weight of reactants and may be added before or after completion of the B stage. Inhibitors for addition to the resins to prevent infusibilisation are polyhydric phenols, such as hydroquinone or resorcinol and aromatic amines, such as beta-naphthyl - para - phenylene - diamine. The final infusible resin may be rendered plastic by malaxation on rolls in presence of organic liquids or solids, e.g. acetone, "Cellosolve," (R.T.M.), camphor. As modifiers there may be added (a) oils, e.g. soya, linseed, perilla, fish, tung, sunflower, oiticica, dehydrated castor, cottonseed, coconut and castor oils, or acids obtained by hydrolysis of the oils; (b) acids, e.g. lactic, benzoic, chlorobenzoic, salicylic, mucic, acrylic, D 1-cyclohexene carboxylic, vinyl acetic, allyl acetic, propiolic, tetrolic, ethyl propiolic, propyl propiolic, vinyl acrylic, sorbic, butyric, propionic, stearic, palmitic, glycolic, chloro-acetic, chlorpropionic and cinnamic acids; (c) esters, e.g. dibutyl phthalate, triacetin and tricresyl phosphate; (d) cellulose derivatives; (e) protein plastics; (f) natural resins, e.g. rosin, shellac, copal and dammar; (g) synthetic resins, e.g. phenol-aldehyde, urea-aldehyde, polyamides, and those formed from coumarone, indene, furfural, cyclohexene, styrene, alpha-methyl styrene, vinyl chloride, vinylidene chloride, vinyl acetate, methyl acrylate, methyl methacrylate, derivatives of some of these resins, such as polyvinyl alcohol, polyvinyl acetal, or by the polymerization and copolymerization of conjugated diolefins such as butadiene, the pentadienes, the hexadienes, the heptadienes, the octadienes and the nonadienes, or from those compounds having two or more polymerizable non-conjugated double bonds, e.g. unsaturated aliphatic polyesters of saturated polybasic acids such as divinyl, diallyl and dimethylallyl esters of oxalic, malonic, citric and tartaric acids and the corresponding triesters of citric acid, the unsaturated polyethers of saturated polyhydric alcohols, e.g. divinyl, diallyl and dimethylallyl ethers of glycol, diethylene glycol and the corresponding di- and tri-ethers of glycerol, the unsaturated aliphatic organic polyesters of polyhydric alcohols, e.g. acrylic and methacrylic polyesters of glycol, diethylene glycol, glycerol; the unsaturated aliphatic monohydric alcohol esters of unsaturated monocarboxylic acids, e.g. vinyl, allyl and methallyl acrylates and the unsaturated esters of aromatic dibasic acids, such as divinyl, diallyl and dimethallyl phthalate; (h) naphthalene, anthracene, chloronaphthalene, acetanilide, pitch, asphalt, gilsonite, asbestos, sand, clay, talc, mica, wood flour, rotten stone, cotton and gelatine. In examples: (IV) 25.6 parts of polyallyl acetate obtained by the polymerization of allyl acetate were mixed with 5.7 parts of diethyl phthalate, 47 parts of ethyl alcohol and 0.16 part of metallic sodium as catalyst. The mixture was heated under reflux conditions in the presence of nitrogen with vigorous stirring. Another addition of 0.16 part metallic sodium was made during the reaction. The temperature was held at about 100 DEG C. for 6 hours, at which time the mixture was subjected to distillation to remove the ethyl acetate formed and unreacted materials. The product was a pale tan viscous liquid. (IX) An alkyd resin was formed by reacting polyallyl acetate, 28.6 parts, diethyl phthalate, 19.1 parts, and ethyl alcohol, 100.7 parts, with 0.29 part of metallic sodium as catalyst in the manner outlined in the preceding example. A solution of the product was refluxed for 2 hours with stirring with 31.8 parts of dehydrated castor fatty acids in the presence of 100 parts of additional ethyl alcohol and 1 part of additional sodium. The resulting resin was washed with hot acetone and dried at 65 DEG C. The resin was a light tan rubbery solid, insoluble in water and organic solvents. (X) 25 parts of polyallyl alcohol obtained by the alcoholysis of polyallyl acetate were reacted with 44.4 parts of phthalic anhydride at about 160 DEG C. The product was an amber hard, brittle solid insoluble in organic solvents. (XI) A mixture of 13 parts of polyallyl alcohol obtained by the alcoholysis of polyallyl acetate and 12.1 parts of phthalic anhydride was heated at temperatures gradually increasing from room temperature to 170 DEG C. over a period of 1 hour and 25 minutes, at which time 22 parts of dehydrated castor fatty acids were added. Heating was continued for an additional 3 1/2 hours at 160 DEG C. The resin was hard, brittle and insoluble in organic solvents. In addition to the uses already mentioned, the resins of the invention are suitable for the preparation of varnishes, baking enamels, paints, lacquers, adhesives, cements, impregnating compositions, stencil paper, insulating compositions, phonograph records, films, filaments, threads, abrasives and floor coverings. The rubbery character of some of the alkyd resins of the invention makes them useful in applications where this property is important. Specifications 565,719 and 566,344 are referred to. The Specification as open to inspection under Sect. 91 comprises also the use of poly-allyl type alcohols prepared by polymerization of allyl type alcohols, which are defined as unsaturated alcohols having an aliphatic double bond between two carbon atoms of which one is directly linked to a saturated carbinol group, e.g. allyl, methallyl, ethallyl, chloroallyl, crotyl, tiglyl and cinnamyl alcohols; 3-phenyl-, 3-tolyl-, 3-xylyl- and 3-naphthyl-propen-1-ol-3; buten-1-ol-3 and its 2- and 3-methyl, 2,3-dimethyl, 4-chloro, 4-phenyl, 4-tolyl and 4-xylyl derivatives; 3-chloro-buten-2-ol-1; penten-1-ol-3 and its 2- and 3-methyl and 4,41-dimethyl derivatives, 2 - methyl - penten - 2 - ol - 1, cyclo - penten-2-ol-1; hexen-1-ol-3 and its 4- and 5-methyl and 4,41-dimethyl derivatives, 2-methylhexen-2-ol-1, cyclohexen-2-ol-1; hexen-1-ol-3 and its 4- and 6-methyl derivatives; octen-1-ol-3; butadien-2,3-ol-1; pentadien-1,4-ol-3; hexadien-2,4- and -2,5-ol-1- and -3,5-ol-2 and 2,5-dimethyl hexadien-1,5-ol-4; 3,7-dimethyl octadien-2,7-ol-1; 2-methylpenten-1-yn-4-ol-3 and hexen-1-yn-5-ol-3. In examples (Cancelled) polyallyl alcohol prepared by polymerizing allyl alcohol in the presence of air or oxygen, is condensed with phthalic anhydride, with or without linseed oil fatty acids in the presence or absence of kerosene or dehydrated castor oil fatty acids. This subject-matter does not appear in the Specification as accepted.