noun
confident work; work one is proud of
Used for a creative work (art, writing, music, etc.) that the creator believes is especially good and is proud to present. Often used when introducing or promoting one's own work.
今回の小説は自信作です。
This novel is a work I'm really proud of.
彼は自信作の絵を展覧会に出展した。
He submitted his confident work, a painting, to the exhibition.