As the adult age stage is so similar to YA, it seems almost wasted. So I was planning to try and use it as middle-aged and make adult sims look older than they originally do.

One thing I was going to do was give them elder's faces on their normal healthy bodies. I was thinking if I take eg the CASP resource called efFace, and add Adult flag to the ages allowed, then edit afFace to take Adult flag off it, can anyone think of a reason the elder face CASP won't fit an adult female sim?

If I use it, when can I expect to see adult sims beginning to use it? Would it be when each of them ages up, or only for sims not yet born or created, or should all adult sims be wearing the elder face when I next start the game? How does the face allocation work?

I cant answer your question but if you can make this work you must use the elder body also
A elder head wont fit on the adult body's

Edit,
It is a cool idea tho
You might pull this of by using all elder resources(face/hair/body and shoes) but still use the adult animations?

No the point is I didn't want the elder stoop and baggy thighs on my middle aged sims, because I was then going to regard elders as being 65 or 70+ when that horrid sack of potatoes look becomes more acceptable. I was however going to reflag some hairstyles and clothes as being only suitable for younger adults.

So I only wanted to apply the elder face for the sake of the default wrinkles. Is the face CASP the whole head mesh then? I thought it would just be the skin tone and texture.

I never thought of the face as a CASP, although it kinda makes sense. Have to look at this when I get time. (Whenever that is.)

Anywho, I believe there's a set of default face overlays, perhaps separate ones for the different ages. Shady has a mod for them: http://www.modthesims.info/download.php?t=403630 You might take a look at modifying that to include weathering.

It strikes me that one of the differences between the adult and young adult stage is that adults should gain weight faster. As we age, our metabolism slows down. Since most of us do not cut back on calories, there is a tendency to get fat.

I already plan to look for an xml that may control pregnancy chances. Should be pretty near 0 for middle aged I guess an xml probably controls weight gain.

oh, you were talking about the textures. i thought you wanted the shape of the face.