It’s the
shirt you’re wearing that’s the culprit. Change
the shirt and the neck texture poofs. Change it back and you’re
all good.
It's been on my
list to play with and figure out what’s exactly is happening.
My unproven theory
at this point is that depending on the shirt what neck texture
the skin uses varies. By default the skin uses the bit of
neck on the body map, on others it uses the neck on the head
map, so literally you need to make 2 necks.
Of course now I
have to experiment and prove my theory right or wrong, always
loved chemistry lab
I’ll be back
and post my results...
..........................................................
Yep, 2 necks are
flipping.
Here’s what’s
happening...
I made a basic
white skin, texture map intact and made the only color on
the 2 necks.
The neck on the
body is blue
The neck on the head is red.

Now here is the same skin texture with two different shirts.

On IMVU and some
developer meshes the skin maps only with the neck from the
head.
Yet on some other
developer meshes the body neck texture is used. Looking at
the snaps some of the head neck is at the top and the bottom
half of the neck is the body neck texture.
I took a random
product sampling from the catalog to find a pattern.
Head
Neck
All IMVU I tested...
Abby Shirt, Hoody, Baby Tee, Button Downs, Daisy Oxford,
Spaghetti Straps
Tight top in Deep Purple Ruth (shown)
Wedding Dress M9
Bandeau top Ruth
Black Lether Coat M9
Brocade Corset Ruth
Body Neck
'Sandy' Bodysuit Cass (shown)
EZ Tee KittenKat
Neo-Stiches White top WM
Little Black Dress Cass
Bigger Bust KimberlyLin
The Dolly KittenKat
The clothing meshers
neck choice will determine the neck used. Composite products
that that use the neck will all use the body neck and not
the head neck.
The solution for
skinners adding neck details is to make the neck pattern on
both necks so no matter which neck the mesh calls on your
skin pattern stays intact. Unfortunately they are not mapped
the same so it's more than just a copy paste.