Abstract: A plastic sheet packing or packing member of the flat folding bag type, primarily for pipe tobacco, the mouth opening of which is sealed in a welded manner enabling it to be opened without rupturing the sheet materials adjacent the mouth opening. The mouth is closed by a type of welding providing a good sealing effect though being releasable by mechanical pull to facilitate opening of the packing. The opposed surface portions of the mouth area may be welded direct to each other in this manner, or a separate, removable closing strip may be arranged along and across the mouth and secured by the releasable type of welding. This type of welding may require mutually different materials to be joined, and this is obtained either by the use of said separate strip or by using a sandwich sheet for the packing itself.