Abstract: A method of forming articles from thermoplastics sheet by free-blowing, without use of moulds, in which the sheet is pre-heated to elastic state, free-blown by establishing a differential fluid pressure between opposite faces of the sheet and maintained at optimum temperature during the period of free-blowing by heating or cooling by heat-exchange between the sheet and fluid flowing over at least one face. Apparatus for performing the method comprises a tank diversible into two halves adapted to hold the sheet edgewise in between, the differential fluid pressures being established between the volumes in the two halves and fluid flow over the face of the sheet being established in one half.