I also have loads of the old ‘pulp’ SF books, which are all of a much smaller size, typically 100 pages on thin paper, in a small format. These are very portable and I sometimes take one to read on the tube. They all have lurid images in bright colours so some things don’t change!
![Classic SF 50s](http://www.notesstoryboard.com/wp-content/uploads/2016/07/classic-sf-50s-300x222.jpg)
Check this out:
See some classic Science fiction covers here on Barnes and Noble >