<http://schema.org/description>
"&lt;p&gt;One recently introduced process builds molds from the inside out, layer on layer, to form internal features and geometries not possible with conventional metalworking techniques.&lt;/p&gt;"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mmsonline.com/articles/added-options-for-producing-39impossible39-shapes>