trying out a pen; test-writing
Refers to the act of testing a pen or writing instrument by scribbling or writing a few characters, often to check ink flow or nib condition.
I bought a new fountain pen, so I tried it out with some test-writing.
There is paper for test-writing at the stationery store.
Compound of 試し (trial, test) and 書き (writing). The exact historical derivation is uncertain, but the word transparently means 'test writing'.