UPDATE - 11/2@12:27PM: Thanks to reader Paul P I now have the picture of Alex with The Bag from page 8 of the book's photo section.
No Regrets is the new autobiography from original KISS guitarist Ace Frehley. The book just released today and there's a Rush mention on pages 188-9 in Chapter 13 - Fast Cars, Celebs, and Betty White:
I have so many road stories, but one that always comes to mind is the tour we did in the summer of 1975 with Rush opening for us. I always liked Rush (and still do). After a few weeks on tour I started to get to know the guys in the band, and their very funny tour manager, Howie. One thing led to another and before long Peter and I were getting visits from the Rush boys. It usually turned into late evenings filled with beer and grass and whatever else was around. Alex Lifeson, the band's guitarist, used to do this hysterical routine with a large paper laundry bag. He'd draw a ridiculous giant face on the bag with a black marker and put it over his head with a couple of holes poked in it so he could see and breathe. Everyone in the room at this point was either drunk or stoned, but usually a little of both. Anyway, Alex would go into this routine with the bag over his head and while smoking a joint out of his eye he put everyone into total hysterics. He really milked the routine until everyone was gasping for air!
Ace has mentioned this story in the past, specifically in this 2006 radio interview with Eddie Trunk. Apparently there's a photo of Alex with The Bag on page 8 of the book. If anyone purchases the book, please scan it for us! Thanks to RushFanForever for the heads up.