So I'm starting to create a custom materials library for my company.  I decided to take a risk, do the premium membership on matweb and download a bunch of materials (things we often use at our company that are not exactly listed in the default SW materials).  While most of them seemed to import with the relevant physical property info (not all though; bummer) - I still need to apply appearances.  I pulled makrolon (polycarbonate) in -for example - as one of the materials in the library I created and went to assign a clear plastic appearance to it (using one of the default SW appearances for "polycarbonate plastic" under the "Clear Plastic" folder (under "Plastics").  When I applied the appearance I could see that it changed the color; but the default appearance remains opaque (and oddly; not consistent - it's shinier on the top side for some reason - and makes no difference if I flip the part; as one would expect if it were some kind of lighting setting)....but my biggest concern is that it is not transparent (not even a little bit transparent).  How do I change the default transparency appearance on a custom material file?

On the same note; SW appearances/displays are very confusing for me...I haven't dealt enough with marketing/advertising to really dig into display settings and appearances; but it never seems to be a straight forward matter to make something look the way I want it to.  Can anyone recommend a good resource on how the heck to apply and manage appearances the 'right way' in SW?

Thanks!