Original vintage magazine ad, NATIONAL SEAL COMPANY, INC., of Brooklyn, NY.  Distinctive Closures Known The World Over For Quality and Beauty.  A Caps for Every Purpose.  For bottles, jars.  Old 1938 glass industry advertisement.

On the reverse side (see Additional Images tab) is CROWN CORK AND SEAL COMPANY of Baltimore, MD.   Making Sure. Crown Closures.  Better Sealing for Better Business. Photo Courtesy of Pennsylvania Railroad.
Approximate size 8 x 11 inches.