PACKING.
Sheet packing is often times made in a press, like corrugated matting. The varieties, however, known as gum core have to go through a different process. Usually a core is squirted through a tube machine and the outside covering of jute or cotton, or whatever the fabric may be, is put on by a braider or is wrapped about it somewhat after the manner of the old fashioned cloth-wrapped tubing. The fabric is either treated with some heat-resisting mixture or something that is a lubricant, plumbago and oil being the compound. Other packings are made from the ends of belts cut out in a circular form and treated with a lubricant. There are scores of styles that make special claims for excellences that are made in a variety of ways, but as a rule the general system as outlined above is followed.