Returns or sets the current line width. The line width value specifies the diameter of a pen that is circular in user space, though device-space pen may be an ellipse in general due to scaling/shear/rotation of the current transformation matrix (CTM).

When the description above refers to user space and CTM it refers to the user space and CTM in effect at the time of the stroking operation, not the user space and CTM in effect at the time of setting the LineWidth property. The simplest usage makes both of these spaces identical. That is, if there is no change to the CTM between setting LineWidth and the stroking operation, then one can just pass user-space values to LineWidth and ignore this note.

As with the other stroke parameters, the current line width is examined by Paint.Stroke, but does not have any effect during path construction.