a folding method and device , whereby a tubular wrapping is formed about a product by inserting the product inside a u - shaped pocket together with a sheet of wrapping material , a first lateral portion of which is interposed between the product and a first lateral wall of the pocket , and a second lateral portion of which , opposite the first , is folded outside and beyond the pocket and crosswise to the first lateral portion ; the tubular wrapping being closed by moving the first lateral wall of the pocket outwards , simultaneously moving a contrast member onto the first lateral portion , and then folding the second lateral portion , by means of an external folding member , onto the product and so as to overlap the first lateral portion ; and the tubular wrapping being fixed inside the pocket by withdrawing the external folding member , simultaneously closing the first lateral wall onto the product , and withdrawing the contrast member from the pocket .