So I have found that these pages are needed for progressing crafting to grandmaster and illustrious. I have also been able to discover that in nightmare difficulty you get the pages, in hell you get the tomes and then in inferno you get the Tome of Secrets.
What I am looking for is areas where I can go and find them more often. Are they world drops from destroying the environment and/or opening chests and if there is a preference which one? Or are they mob drops and, again, is there a preference towards a type of mob?
Best Answer
Total Blacksmith Leveling Cost and Materials
Source
Total Jeweler Leveling Cost and Materials
Source
Drop Rate and place
Source
Aside the above information, there are reports about pages droping in ACT IV normal.¹²
I believe is because some monster have a iLv in ACT IV normal equivalent to the early monsters from nightmare (Like the gems, where you get better quality based on the item level), but I couldn't find source to support (or to invalid) this information. (still looking)