1pen 
/ˈpɛn/ noun
plural pens /ˈpɛn/ noun : a writing instrument that uses ink [count] ▪ She signed her name with a pen. [noncount] ▪ She signed her name in pen. — compare pencil
put/set pen to paper
: to write or begin to write something
▪ She thought about writing a novel for several years before she finally put pen to paper.
▪ She thought about writing a novel for several years before she finally put pen to paper.
