@thomasfuchs i bought e.gerber Mylites 2 for the bags, they are more crinkly but archival quality. I got e.gerber half-backs for the magazine boards.
The boards I was using were starting to yellow and I figured flipping thru comics collector forums was the best source of what's best.
I don't know about BYTE magazine size but the first several years of OMNI required I trim the boards to 8.5" x 11.25". I didn't mind, Omni is amazing and shines such a bright light on tech industry POV nowdays.