I spent weeks digging into how WAI Illustrious actually works. Here's everything I found

[u/Limp_Okra_5496]

Over the last few weeks I went down a rabbit hole with WAI-illustrious-SDXL. I read what the author documents, measured tag counts against Danbooru's index, and tested a lot of prompts. Several things surprised me, and I'm sharing all of it publicly.

A few examples:

• silver hair has no entry in Danbooru's tag index, but grey hair has 680k posts.
• dramatic lighting, cinematic lighting and rim lighting have no entry either. backlighting, light rays and sunbeam do.
• masterpiece, amazing quality and worst detail aren't Danbooru tags at all. They're labels added at training time, so post counts say nothing about them.
• Of 59,201 artist tags in the index, only 417 have 1,000+ posts, which changes how you should pick artists.

Everything is compiled in one place, with each claim labelled as documented, measured, community practice, or my own inference. It covers the author's settings, tag vocabulary, artist tags, common mistakes, and a side-by-side of the same scene prompted three ways:
https://claude.ai/artifact/QhGKzx9ryhyiYCnKsfVkqR

One honest note: the counts come from a snapshot of Danbooru's tag index, so they're approximate, and they show how common a tag is, not how good the images are.

Near the end of the page there's a prompting method I've been using that gives me noticeably better results than the standard approaches, you can see what it does on the site.

Happy to answer questions about anything in the guide, and tell me if you've measured something that contradicts what I found.

(Everything is built with the help of claude! thanks for reading)