Illustrious negative prompts

The WAI-Illustrious author recommends a short negative prompt: bad quality, worst quality, worst detail, sketch, censor. It only does anything when CFG is above 1. Fast setups that run at CFG 1, such as DMD2, Lightning and Hyper LoRAs, skip the negative entirely.

The recommended negative prompt

From the WAI-Illustrious model page:

The same page warns against long negative lists: they “will actually reduce image quality and make it more blurry.” Its recommended settings are 15–30 steps, CFG 5–7 and the Euler a sampler.

Why your negative prompt isn’t working

If you run WAI or any Illustrious model with a speed LoRA at CFG 1, the negative is thrown away before sampling. In ComfyUI’s sampling_function, when the CFG scale is 1.0 the unconditional pass, the one that carries the negative prompt, is set to nothing and never computed. That’s a deliberate speed-up: at CFG 1 the negative would cancel out anyway.

SirenRender’s free anime tile runs at CFG 1, so a negative prompt can’t change its output. The platform sets the negative prompt itself on every tile, and it can’t be edited.

What CFG does on the free tile

The free tile lets you raise CFG to 2. At 2 the image gets punchier and the model starts to listen to the built-in negative, but the DMD2 LoRA is tuned for 1, so push past it with care. The HD anime tile (1 credit) runs the full model at CFG 5 and 30 steps with a hi-res pass.

What to do at CFG 1 instead

• Say what you want, not what you don’t. If you get busy backgrounds, add simple background instead of negating clutter. If you get open mouths, add closed mouth.
• Use the rating tag. general does at CFG 1 what people try to do with nsfw in the negative. See the prompt guide for the side-by-side.
• Change the seed. A bad hand on one seed is usually fine on the next. Every prompt in the library shows four seeds for that reason.