Backface material in Flamingo

Good morning,
to setup a render with a tinted glass, reflective on the outside face and semi-transparent from the inside. I have assigned a decal with an alpha facing backward, unlike in other rendering engines where backface can be set for each object property. In Rhino display modes (shaded, rendered…) the backface can be set as cull, single colour or a material, but this feature is not in the render. Also on my version, Flamingo NXT 5, I can’t find the masking properties.


The transparency can only mask the texture itself, but editing the decal doesn’t affect in the rendering results on my machine, only the rendered model view, the command FlamingoClearBitmapCache didn’t do the trick either.