Material properties in ArtisGL has "Opacity" option and Alpha Map property. Opacity controls transparency of the object. But in some cases transparent materials can be incorrectly displayed because of rendering order issue. To resolve this issue use Render Order setting in material properties.
Increasing render-order will make this material layered. It means if render order higher than 0 then this material will be rendered AFTER other materials render. Transparent material should be displayed over the non-transparent details. By default system adjusts rendering order but is some cases adjustment may be incorrect. So use this option to adjust rendering to your needs.
