It made bubbles of, per wikipedia,
polyvinyl acetate dissolved in acetone, with ethyl acetate plastic fortifiers added. The acetone evaporated upon bubble inflation, leaving behind a solidified plastic film.
Which looked like,

↓↓ VOLUME WARNING! LOUD DISTORTED AUDIO!! ↓↓
And here’s a 1970’s commercial. Especially headphone users, would recommend starting low and easing into it.


Sounds interesting, but the link is coming up “not found” for me. I tried a forum search for “atomic”, and “gilbert”, but didn’t turn anything up.