The present invention relates to a method of manufacturing water-soluble containers using a horizontal intermittent motion thermoforming machine comprising locating a first water-soluble film over a mould containing a plurality of pocket forming cavities in a 2-dimensional array, each cavity being surrounded by a planar surface of the mould on all sides in which the shortest dimension of the planar surface between two adjacent cavities is at least 3 mm and between an edge of the mould and the closest cavity is at least 1.5 mm, thermoforming a first film to produce a plurality of pockets, at least partially filling the pockets with a composition and sealing the plurality of the at least partially filled pockets. The cavities are positioned in the array such that there are a plurality of continuous strips of uninterrupted planar surface of the mould from a leading to a trailing edge of the mould, for receiving support means fitted to the machine for supporting the film.