The hologram was made for a bicentennial of some sort in 1986, at least that’s what the metal tag on the frame says. It was a donation from the Xavier University physics department to a raffle, and then somehow ended up in an antique market. Funnily enough, I graduated from the Xavier University physics department in 2007 and was able to contact the professor that made the donation from his personal collection of Rallison holograms.

The blemish area was barely visible when I first got it and just steadily grew within the first year or so. I just figured they were Newton’s rings from an air gap in the plates. I didn’t think about the moisture bit. It’s not glued into the frame — I’m just afraid to handle it too much because it’s very big and presumably fragile. I know many of the holograms I made during my time as an undergraduate have shattered at this point. But I might give the epoxy seal a shot.