Button copy is a type of physical design for road signs in the United States.
In daylight, the buttons visually blend with the white sign legend elements and so are minimally conspicuous.
Thus the sign is made sufficiently conspicuous and legible for adequately fast and accurate recognition and interpretation by drivers.
Button copy has been supplanted by a newer technology: retroreflective sheeting made by various manufacturers in numerous colors and grades.
[3] However, at night, retroreflective sheeting is clearly visible and readable at much longer distances than button copy.