How to use negative prompts

You should reading the prompting guide before proceeding. This will give you an idea of where to find tags and how to use them effectively.

What Are Negative Prompts?

Negative prompts are specific instructions given to an AI model to exclude certain things from the generated images.

One way to think of them is as filters, making sure that unwanted things do not appear in the final image.

They are particularly useful in fixing common issues such as poor quality, incorrect anatomy, or undesirable styles.

I actually recommend leaving the negative prompt blank, unless there is something you specifically want to exclude.

Furthermore: on BetterWaifu there is already a negative prompt used under the hood if you have “Use recommended preprompts” setting checked.

More info on this here. TLDR: a standard quality-enhancing negative prompt is used in every generation when that setting is checked, it is just kept hidden for ease of use. This negative prompt is “score_4, score_3, score_2, score_1, worst quality, bad hands, bad feet,” which can (and should) be used with Pony Diffusion models.

Are long negative prompts good or bad?

With all models on BetterWaifu, it’s recommend to use short negative prompts.

Very long negative prompts are a hallmark of earlier Stable Diffusion models (SD1.5 & SDXL). We do not have to do this anymore with the latest Pony-based models.

Example:

Negative prompt: score_4, score_3, score_2, score_1, worst quality, bad hands, bad feet, 3d

Negative prompt: score_4, score_3, score_2, score_1, worst quality, bad hands, bad feet, 3d, 2d, ai-generated, artifact, artifacts, bad quality, bad scan, blurred, blurry, compressed, compression artifacts, corrupted, dirty art scan, dirty scan, dithering, downsampling, faded lines, frameborder, grainy, heavily compressed, heavily pixelated, high noise, image noise, low dpi, low fidelity, low resolution, lowres, moire pattern, moiré pattern, motion blur, muddy colors, noise, noisy background, overcompressed, pixelation, pixels, poor quality, poor lineart, scanned with errors, scan artifact, scan errors, very low quality, visible pixels

You can see the long negative prompt does not make a big difference. You could even argue the second image is worse because of the anatomy mistakes in the hand.

When should I use negative prompts?

Normally I don’t put anything in the negative prompt, unless there is something coming up that I definitely don’t want.

Here’s an example:

Prompt: naked apron, sideboob, orange apron, drill, tools, saw, indoors

When I used this prompt, I intended to create a character in a workshop-like environment. However, because the AI strongly associates the apron with a kitchen, it renders a kitchen even without me prompting for one.

I can use the negative prompt to get rid of the kitchen:

Prompt: naked apron, sideboob, orange apron, drill, tools, saw, indoors
Negative prompt: kitchen, food

That’s much better! You can use the negative prompt in this way, to remove the things that you don’t want but are still appearing due to some association the AI is making.

Other situations

Here are examples of times you might want to use negative prompts, and the prompts you would use:

Anatomy errors

anatomy error, anatomy mistake, broken anatomy, broken pose, extra arms, extra digits, extra fingers, extra legs, extra limbs,

Watermarks and Logos

logo, patreon logo, sample watermark, sticker, sticker overlay

Undesirable Style/Medium

abstract, amateur, black and white, drawing, flat colors, icon overlay, meme, monochrome, ms paint, pixel art, screencap, sketch, sketchy, symetrical

Undesirable Background

empty background, gradient background, no background, random background, simple background, white background