How to use roughen brush tool in coreldraw ?

In the toolbox, click the Roughen brush tool . Point to the area on the outline you want to roughen, and drag the outline to distort it. Type a value from 0.01 to 2.0 in the Nib size box on the property bar. Type a value between 1 and 10 in the Frequency of spikes box on the property bar.