Splendid Isolation

(My original Judges Guild Judge's Shield (1977), DM view.)

Almost always I have used a dungeon master shield. 

• In 1978 I picked up the original first published Judge's Shield by Judges Guild. This was really made for OD&D using the Greyhawk supplement, but it worked for our D&D gane until the Dungeon Masters Guide was released around the summer of 1979. (I made a canary yellow Advanced Labyrinth Lord screen in honor of my old and worn Judges Guild screen.)
• During this period of the late 70s through the 80s is was also common for Dungeon Master's to just use gatefold record albums. This did not provide any helpful tables, but did hide the DM's notes and often the record albums were chosen for their trippy art.
• Later (not sure when) I acquired or most likely shared the T$R AD&D (1st Ed.) Dungeon Master's Screen. This is probably the most classic and well known screen, even had a separate 2-panel screen just for psionics!) 
• When I restarted our game with new rules in 2004 I used the Ver. 3.5 D&D Deluxe Dungeon Master's Screen which was my first landscape paneled screen (my older screens basically had panels in portrait orientation). I really enjoyed being able to see over the screen better without having to stand up.
• When I developed a 3rd Ed./AD&D hybrid rules we used in our game starting in 2012 I found the original 3rd Edition DM screen from 2000 and just clipped a whole bunch of alternate tables on top the screen.
• During 2018 when we switched to a modified 5th Ed. I used Dungeon Master's Screen, Reincarnated (2017) which was the first landscape-panel screen I used in game play and was hardbacked instead of cardstock (4th Ed. had the first landscape/hardback screen I ever purchased, however we never ran our campaign in 4th Ed.) I ended up over time covering this screen in stickers.
• When we switched to Advanced Labyrinth Lord retro-clone in 2019 I made the aforementioned canary yellow Judges Guild tribute screen.
• I also created homemade ref screens for Arduin games I've run for Green Hell in 2022 and a more generic Arduin screen in 2023. And also made a little mini-screen for Lamentations of the Flame Princess off of art for a future screen that hasn't yet been published.
• During 2024 we first started our new 5th edition campaign I used the 5e screen from the 5e Wilderness Kit (the screen art is very cool), then when the 2024 revision books were released switched to the 2024 standard screen.

So what is the deal? I often have DMed without a shield, in particular by the 1990s when I knew the AD&D (1st ed) rules like the proverbial back of my hand. We also did a lot of "theatre of the mind" style games without miniatures and adventures were built out of imagination in real time improvised off simple maps and small sets of notes.

For me at least I enjoy having a wide variety of tables and notes for situations that might come up during a game. I am also often translating scenarios from different rules editions so want to make adjustments on the fly. Also cool and provocative player-facing art on a screen helps set the vibe a little.

And I guess I do like DMing from the far side of the table, away from the door, where a screen provides some privacy when I get up to pee and still have my maps and notes somewhat hidden. Unless someone wants to obviously sneak a peak.

Ha. mostly though, if I am being honest, when I am furiously going through a variety of materials trying to find that note or rules section or piece of a dungeon I am hacking for my campaign, it really is best for my players not to see that.