ClearType font smoothing is a function of Windows, not WindowBlinds. WindowBlinds can apparently take advantage of cleartype to improve performance, but you have to enable it in Windows first.
Open your Display Properties and click on the Appearance tab. Then click the Effects button. On the dialog window that opens, check the second checkbox (labeled "Use the following method to smooth edges of screen fonts") and select ClearType from the drop-down menu.
