noun
written letters; handwriting
Refers to characters or letters produced by writing, as opposed to printed type. Can denote the style or quality of handwritten script.
彼の書き文字はとても読みやすい。
His handwriting is very easy to read.
この書類は書き文字で記入してください。
Please fill out this document in handwriting.
手書き is a more common word for handwriting or something written by hand, often used as a noun or suru-verb. 書き文字 emphasizes the characters themselves rather than the act of writing.
Compound of 書き (kaki, 'writing', continuative form of 書く) and 文字 (moji, 'character, letter').