In multiple interviews, Tamaki explains that her identity shapes the lens that she sees through, but she does not make conscious effort to work these themes into her illustrations and designs.

The second part consists of a wordless graphic narrative titled The Tapemines, which tells the story of two children in a surreal landscape featuring "forests of cassette tape".

[10][11] Skim (2008) is a critically acclaimed graphic novel illustrated by Jillian and written by her cousin Mariko Tamaki.

[12] It tells the story of a young high-school girl and touches on themes of friendship, suicide, sexuality, and identity.

[13] Indoor Voice (2010) collects Tamaki's drawings, illustrations and comic strips and is part of publisher Drawn & Quarterly's Petit Livre series.

In 2015, Drawn & Quarterly published SuperMutant Magic Academy, a collection of Tamaki's web comic of the same name from 2010 to 2014.

[24] In June 2017, Drawn & Quarterly published Tamaki's graphic novel Boundless, a collection of short stories.

[26][27][28] A review in The Atlantic described the book as "an ambitious and eclectic set of tales, [that] focuses on the interior lives of unexpected subjects.

The covers were designed for three classic literature books: Emma by Jane Austen, The Secret Garden by Frances Hodgson Burnett, and Black Beauty by Anna Sewell.

[39]This One Summer, created by Mariko and Jillian Tamaki, ranked #1 on the list of top ten most banned and challenged books in the US in 2016.

The main reasons this book was challenged were for its LGBT characters, drug use and profanity, sexually explicit content, and mature themes.