Once cooled, the band is removed to prevent residual water between the jar threads and the lid from rusting the band.If the jar seal is properly formed, internal vacuum will keep the lid tightly on the jar."Patent Nov 30th 1858," signifying the date of Mason's patent, was embossed on thousands of jars, which were made in many shapes, sizes, and colors well into the 1900s.Since they were made in such quantity and used for such long periods, many of them have survived to the present day.
While the bands are reusable, the lids are intended for single use when canning.The stopper or lid was typically made from metal, porcelain, or ceramic, while a rubber gasket was used to seal the container. The sealing surface on the jar was a "shelf" that supported the lower edge of the lid.Putnam modified de Quillfeldt's design so that the lid was secured by centering the wire bail between two raised dots or in a groove along the lid's center. A rubber gasket between the shelf and the bottom surface of the lid formed a secure seal when the wire closure was tightened.By far the most popular and longest used form of closure for the glass canning jar was a zinc screw-on cap, the precursor to today's screw-on lids.It usually had a milk-glass liner, but some of the earliest lids may have had transparent glass liners.The court ruled that Mason's delay in protecting his patent indicated he had abandoned his invention in the intervening years between 18 and had forfeited his patent.