You specify an underlay’s position, scale, or rotation when you attach an underlay file. You can also modify these settings later during the drafting process.
By default, the insertion point of a file is 0,0,0, its scale factor is 1, and its rotation angle is 0. You can use general modify commands such as move, scale, rotate, mirror, array, and so on. After you select an underlay, you can alter it using the options in the Properties Palette.
Double-clicking an underlay opens the Properties palette for that underlay.
While underlay behavior generally mimics raster image behavior, one exception is the way that grips work. In this case, the behavior more closely parallels block behavior. Normally, an underlay displays only a base grip. You can use a base grip to reposition an underlay in a drawing. If you create a clipping boundary, additional grips display for each corner of the boundary.
The grip for the base point is the lower-left corner of the underlay.