A kind of tape used to create padding on bicycle handlebars. Usually on road bikes, but sometimes found on the bar ends of mountain bikes.
In the olden days, bar tape only came in cork, leather, or cloth. Cork bar tape is still seen today, but most modern bar tape is made of some sort of plastic foam, sometimes with bits of cork impregnated into it.
In the late 60's and 70's, smooth plastic bar tape was in vogue, though it's nearly impossible to find these days. It's hard to understand why they were ever used, since there was hardly any padding on bars wrapped with plastic tape.
Bar tape is usually 1 inch in width, though cloth tape comes in 1/2 inch widths.