Sketching is useful for creating irregular boundaries or for tracing with a digitizer.
You can draw freehand sketches and then convert them into lines, polylines, or splines.
With the SKETCH command, you create a series of tiny segments. Setting the SKETCHINC system variable, you can control the incremental length of each segment. With the SKPOLY system variable, you can control whether the result is a series of independent line segments, a polyline, or a spline (the SKTOLERANCE system variable controls how closely the spline matches the original sketch).
You use Tablet mode with a digitizer. Sketching in Tablet mode is useful for such things as tracing map outlines from paper directly into a drawing. You cannot turn off Tablet mode while sketching.
When Tablet mode is on, you can configure the program to map the paper drawing's coordinate system directly into the world coordinate system. Thus, there is a direct correlation between the coordinates where screen crosshairs appear, the coordinates on the tablet, and the coordinates in the original paper drawing. After configuring the program to match the coordinates of the paper drawing, you may find that the area shown on the screen is not the area you need.