An adhesive strip used for hermetically and releasably sealing metal cans which may contain coffee or other perishable commodities comprises a flexible, non stretchy, tape backing member which neither breaks nor elongates more than 25% under a tension of 4 pounds and is capable of being pulled back upon itself without rupture, and a smooth, uniform coating of thermoplastic, heat activatable, non-tacky adhesive of 1/2 to 10 mls. thickness which affords continuous resistance to dead load shear of at least 25 psi at 120 DEG F without the tendency of the lid and container portions of the can to separate at the adhesive strip, the adhesive strip being adherable to clean tin plate under heat and pressure to provide a peel resistance of 1 to 6 pounds per 3/8 inch width at 41 DEG -104 DEG F, the instantaneous peel resistance at 40 DEG F to 100 DEG F varying no more than \sB50% from the average at that temperature, and the average peel resistance at any such temperature varying no more than \sB50% from the average peel resistance at 75 DEG F. The backing may have low-adhesion back size coatings such as are disclosed in British Patent Nos. 645,057 and 683,927. The backing may be treated to improve the anchorage of the adhesive e.g. by etching or roughening. The backing may be of a soft metal, or a plastics such as polyethylene terephthalate which has been oriented by stretching. In the Examples: a soft aluminium foil is primed with a vinyl chloride-vinyl acetatemaleic anhydride copolymer and coated with adhesive compositions comprising nitrile rubber prepared from butadiene and acrylonitrile, a bisphenol A-epichlorohydrin copolymer, with or without a partially hydrolyzed vinyl chloride-vinyl acetate copolymer; a soft aluminium foil with the same primer is coated with an adhesive composition comprising a polyester-based urethane polymer, with or without a partially hydrolyzed vinyl chloride-vinyl acetate copolymer; a polyethylene terephthalate film, biaxially oriented, is coated with an ethylene-vinyl acetate copolymer by direct extrusion. Other film backings mentioned are stretch oriented bisphenol-epichlorohydrin copolymer, stretch oriented polycarbonate film where the adhesive is applied as a hot melt coating or by transfer coating, unplasticised polyvinyl chloride. Other adhesives are polyether urethanes and mixtures thereof with polyurethanes and vinylcopolymers.