The reason the ones at the Smithsonian are porcelain is they were having a show called "American Porcelain".

VOA: special.2009.09.09

"One is that it is designed to show people that there is no reason to stigmatize people who are HIV positive.

VOA: standard.2010.05.29

"People have been demonstrating these sets for a long time. But the reason it is coming out now is because of a new standard for Blu-ray players that can show movies in 3D."

VOA: standard.2010.03.11