Back in my school days' years ago, I had a schoolmate who was insane enough to use blood in a fountain pen. He used mesmenir or hashmal blood, not his own (because we persuaded him not to). He just wanted to see if blood would work in a fountain pen – and found it clotted and clogged up the thing overnight.
Then the oddball schoolmate went around the school labs and found various anticoagulant-type solvents or reagents. Mixed with blood, it worked for maybe two or three days, but the pen's innards also got destroyed by the chemical reaction.
Then he found the only way to use blood for writing was by dip pen, the traditional method.
And then the document stank to high heaven from decomposition, molds and various other disgusting effects.
If blood were an efficient writing substance, ink wouldn't have been invented.
