Purpose

Create more variety an accuracy in breast sizes, and allow for prompting of more descriptive breasts, while also improving the quality of the images.

In addition, improve the looks of the breasts in general and hopefully reduce the slight ai look to skin and faces.

I am working on creating several, of which this is the first.

Settings from testing:
Strength: 1.0
Samplers Tested: euler, res_multi_step
Steps: 25 or 30 is good for initial look.
40 to 50 give the best results

Prompting

Trigger words: a-cup, b-cup, c-cup, d-cup, dd-cup, f-cup, g-cup

These trigger words, along with flat-chested or flat chested are what is used to create different breast sizes. Further keywords listed below help to define other characteristic.

Nude, topless and bottomless: Helps guide the output to the appropriate lack of clothing.

Enhanced, round, natural: Adding one or more of these words with breast will push the output towards the appropriate breast type.

Small, medium, large, very large: Adding one of these words will suggest the appropriate breast size. This is very finicky, but often describing body type helps.

Skinny, thin, slender, fit: Describes the body type, and tends to aid in making the breast sizes more accurate. Often you will have to add the word physique to this, but it's not consistent. However it also tends to drop breast size by one.

flat chested, flat-chested:: To produce a flat chested woman. Z-Image seems to ignore this quite often, but adding "skinny" or "slender" does increase the probability.

You can combine them such as:

"A skinny fit woman with medium-sized perfectly shaped b-cup natural breasts"

"She has large round dd-cup enhanced breasts"

"medium-sized natural c-cup breasts"

Limitations

Since it was not trained on the full body, but waist up, and focused on the chest one side effect is it can occasionally produce worse anatomy full body.