I used to ride 700x19 tires. They were so skinny the gave absolutely no cushion. I still have them in the basement. I recently checked the latex tube I used with them, prompted by a thread the other day here, and the tube disintegrated.

This gets me thinking that I should try mounting these again just for kicks on a modern wheel and see how it feels compared to a Conti GP4000 700x23. I somehow think I'd hate it, or at least my butt would. The stuff we used to put up with, non-padded real leather chamois shorts, hard non-molded saddles, toe clips, downtube shifters, crappy brakes. I still have all of them somewhere.