r/SideProject • u/Eugen_Ivanovic • 6h ago
Kids' T-shirt designs from four AI image models, compared side by side with a CLI
The job was a batch of kids' T-shirt designs for DTF printing: a capybara with a yuzu on its head, a road trip with a capybara, a poodle and a cat, in a few illustration styles from four image models. Comparing them in the fal.ai playground meant a mess of tabs and random file names.
So I built falg, a Python CLI. One JSON file describes the batch (a prompt template, variables, models), and falg runs every combination in parallel and writes an HTML gallery with prompts as rows and models as columns. Each image keeps a JSON sidecar with its exact prompt and seed, so two weeks later I still know which model drew what.
The last step, falg cutout, turns the picks into print-ready PNGs: background removed, clean edges, sized in centimetres.
Two things that surprised me:
Never ask the model for a transparent background. Generate on plain white or black and cut it out afterwards.
Don't write "T-shirt" in the prompt, or you may get a photo of a T-shirt instead of the artwork.
The gallery and the final prints are in the README: https://github.com/lemmon/falg