Brown SPT-1 Lamp Cord Sets is a pleasing option for vintage bridge lamps. 12 foot length and traditional narrow width fits on most lighting from the 20th century.
Standard insulated 18 gauge wire has 2 parallel copper wires. The positive/hot is smooth, neutral/negative - has ribs. U.L. Listed for table & floor lamps were cord is exposed. Stripped, copper-tipped ends simplify wrapping wire around socket screws. Molded-on plugs are polarized and permanently attached to lamp cord. SPT-1 rating has traditional plastic insulation, see below.