1. A graphic hard-copy representation of data, especially of seismic data. See Figure D-17. A graph of amplitude as a function of time gives a wiggle trace, squiggle, or conventional display. Variable area display has the area under the wiggle trace shaded to make coherent events more evident; it often involves a bias and trace clipping. A variable density display represents amplitude values by the intensity of shades of gray. Superimposed modes or combined modes involve the use of both wiggle trace and variable area or variable density simultaneously; they retain many of the good features of each type display. Data are also represented by color encoding (see Fig. C-7), and in other ways. Color displays of different types are shown in Figures D-18 and H-8. 2. A soft-copy representation of data on a cathode-ray tube or similar nonpermanent device.