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.
The grip for the base point is the lower-left corner of the underlay.