By default, the The TransparentContent property is -1, which indicates that the control's TransparentContent property specifies the transparency of the face's content. The TransparentContent property gets or sets a value that indicates percent of the transparency to display the content of the face within the cube. The TransparentContent property gets or sets a value that indicates percent of the transparency to display the content on all faces of the cube. The Transparent property gets or sets a value that indicates percent of the transparency to display the texture / pictures on the cube. The Visible property specifies whether the face's content is visible or hidden. The Enabled property enables or disables the face.

The following screen shot shows the face's content opaque:

The following screen shot shows the face's content semi-transparent: