Button copy is a term describing the method of manufacture of older road signs in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. Button copy signs contain rows of embedded reflectors outlining the legend of the sign, for better visibility at night. The embedded reflectors would stand out against the non-reflective background of the sign, giving the legend better contrast and making it easier to read.
Near the end of the 20th century, newer Scotchlite

Scotchlite

Scotchlite is a retroreflective material made by 3M. Its primary use is in nighttime high-visibility applications, such as 'reflective tape' for cyclists, safety vests for road workers, or the front of many traffic signs...

 retroreflective designs were invented, and provided both a lower cost (due to the ability to be laid out with a computer

Computer

A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...

) and better reflectivity. Because of this, more and more states stopped installing new button copy signs, switching instead to the retroreflective-sheeting signs.