Thanks all, i get it now - the pictures on the Marco site make sense. The pictures on virtuapin aren't clear enough to see how they work.
Looks like the guide would sit up on top of the edge with the one piece going into the grove? If I don't use the guide how do you do it? I was originally thinking of routing a 3/8 x 3/8 L shaped notch in the inside top edge, maybe putting some felt or something down or just silicone the glass in. A light bead would be easy to cut out if it ever needed changing.
Whoa, I would strongly recommend against gluing it. Easy maintenance access is critical. You don't want to have to do anything destructive to get inside.
If you really don't want to route the groove for the plastic guides (which is actually very easy if you have the special router blade I mentioned earlier), probably the next best thing is to cut the spine off the bottom of the guide and just glue or staple the guide to the cabinet. That piece is okay to glue; there's no reason you should ever have to remove it for any routine maintenance work. I think the groove routing is a heck of a lot easier myself, though. You'd have to be really careful removing the spine not to crack the rest of the plastic, and I'm not sure you could get it attached as well with glue as with the spine/groove setup.
I don't think felt or direct grooves in the wood would work that well either. The glass has kind of sharp edges and it's pretty heavy, so a smooth and tough channel for it to slide into is really useful - that's what the plastic guides give you.
Edited by mjr, 24 April 2015 - 12:18 AM.