1.- Alpha Collision

This is a common problem in all mesh bodies, when alpha layers are overlay is common in all 3D games or virtual worlds, have an alpha sorting issue. If you are using one underwear layer with one tattoo layer is possible that tattoo disappear with this overlay effect as i show you in this snapshot.

At this moment are not a solution for this trouble, you can find more informations in this links:

Slink Physique Body FAQ
Q. I have on a shirt and shorts and a tattoo but my tattoo isn’t appearing, I know I turned it on, what can I do to fix it?

A. There is an SL bug that causes layers to vanish if wearing more than one. We have included Alpha Mask buttons on our hud that will help with that issue. When wearing layers, you use the mask that is for the upper layer. Example : When wearing underwear and tattoo you turn on the UNDIES Alpha Mask button. When wearing Pants, shirt and bra use the CLOTHES Alpha Mask button.

Due to this being a ‘fix’ for a bug, there are issues that can still arise. If the clothing you
are trying to mask is sheer or lace, it will not mask properly and will look all broken up

Alpha sorting issues Second Life