Single sided glass mounts are pretty good but film flatness isn't perfect anymore. In all three cases it is a nightmare to get rid off the dust on the extra glass surfaces and there's a risk of fungus over time. Glassless mounts are in general pretty bad but there're no fungus and moisture problems nor an increased dust problem. All in all I am a little bit frustrated with all this mechanical bullshit. I'm looking for the best way to mount slides.
All suggestions welcome.