Abstract: This invention relates to a method of manufacturing a carton from a PET coated material having an initially separate base and side wall sections which are adhered together by melting the PET coating when the respective sections are suitably disposed with respect to one another and in contact. Subsequent application of pressure to different areas of one or other of the base and/or side wall sections ensures a secure bond therebetween. The invention lies in the application of heat to the material and/or coating such that only sections of board which are to be bonded together receive sufficient heat to cause melting of the PET coating, the remaining surfaces not being subjected to heat or only to an amount of heat which can be withstood by the PET coating without compromise of the fluid resistant properties of the PET coating. A hot air blast acutely angled to the coating ensures the correct application of heat in the desired areas. Heat-splash and other problems caused by over heating are thus avoided.