Depending on the meaning:
* If "vignette" refers to a short, descriptive literary sketch:
* Epic: A long, grand narrative.
* Novel: A long fictional story.
* Monograph: A detailed scholarly work on a specific topic.
* If "vignette" refers to a brief scene or moment in a larger story:
* Exposition: A lengthy explanation or detailed account.
* Development: A process of gradual growth or change.
* Climax: The most exciting or important part of a story.
* If "vignette" refers to a decorative design:
* Plain: Simple, undecorated.
* Solid: Without any breaks or interruptions.
* Massive: Large and imposing.
Other possibilities:
* Full-length: This could be used if "vignette" implies something short or incomplete.
* Comprehensive: This could be used if "vignette" implies something limited in scope.
Ultimately, the best antonym will depend on the specific context and the intended meaning.