The present invention relates to a heat-sealable structure comprising an aluminum foil and a heat-seal lacquer, said structure exhibiting a seal strength, according to ASTM F2824, of more than 23 N/15 mm when heat-sealed to another heat-sealable structure comprising an aluminum foil and the same heat-seal lacquer, the heat-seal lacquers of both structures contacting each other for heat sealing, said seal lacquer comprising a copolymer blend comprising: —from 30 to 80% by weight, preferably 40 to 70% by weight, more preferably from 50 to 60% by weight of a copolymer A based on (meth)acrylate ester (co)polymers, olefin (co)polymers and block or grafted copolymers comprising (met)acrylate ester sequences and olefin sequences, —from 20 to 70% by weight, preferably 30 to 60% by weight, more preferably from 40 to 50% by weight of a copolymer (B) based on vinyl halides, vinyl esters of carboxylic acids and ethylenically unsaturated (poly)carboxylic acids.