Abstract: The invention is concerned with a process of making a package of pressurized fluid, said package having an inner container of plastics and a shell of non-extensible material. A tube of flexible plastics is filled with a gas-containing fluid (e.g., beer), and sealed along two parallel sealing zones, spaced from each other by a distance less than the length of the seals, and cut along the seals thereby forming a filled container. This latter is immediately enclosed in a stiff outer shell or sleeve, open at its ends, the filled container's seams being wholly within the shell so that the portions of the container accessible at the ends of the shell are seamless.