How to make AI event posters that don't look like generic slop

AI event posters don't have to look like the same airbrushed pastel slop every local fair defaults to.

In a blog post that racked up 1,334 points on Hacker News, John Hartnup set out to fix the wave of repetitive AI flyers spotted at local events like the Leamington Beer Festival 2026. When ChatGPT produced a generic craft-fayre template for a mock spring fair, Hartnup told the model to treat its first attempt as a "what not to do." ChatGPT pivoted to a clean Bauhaus geometric layout, then generated a menu of alternative styles—including Swiss minimalism, Risograph prints, and 90s rave flyers.

Why it matters: AI models output bland visuals because standard prompts lack design constraints. Specifying real graphic design movements forces clean grids, strong typography, and distinct layouts instead of muddy stock textures.

Here's the gist: tell the model what to avoid. Ask for a specific aesthetic—like Bauhaus, Swiss Style, or Japanese minimalism—and explicitly ban airbrushing, oil textures, or crowd photos.

AI design isn't inherently boring; it just defaults to average until you set strict boundaries.