%fretwork%

n. [ 6th fret + work. ] Work adorned with frets; ornamental openwork or work in relief, esp. when elaborate and minute in its parts. Hence, any minute play of light and shade, dark and light, or the like. [ 1913 Webster ]

Banqueting on the turf in the fretwork of shade and sunshine. Macaulay. [ 1913 Webster ]