Make sure the graphic card could handle using Blended instead of Stippled. If you have a big assembly up using Blended with transparency the assy could bog down and possibly crash, it happened to me a few times.
Under View>Color and Appearance create a new material using the + icon on the right and then under Properties>Advanced (tab) slide the bar under Transparency from Opaque to Clear. That should create a material (with any color settings under the basic tab) that is now transparent. Make sure that the option under View>Display Settings>Model Display>Shade (tab)> the box under Enable for Transparency is checked.