Let's cover specular blending. Skin and cloth don't have the same specular values; they need to be separate and too many vendors(we're all vendors, here, right?!) release products that have latex paint being just as glossy as skin when second skins are used - thats just plain wrong and customers should not have to put up with that. Its just lazy and counter-productive for renders. After all, no one wants painted-in highlights and shadows unless you're making content for a video game!

Again, lets do this right.

• Make another Blender node and set the Blending to "1".
• Plug the mask into the Blending input of the new Blender node.

Lets decide on a Blinn node for the skin's specularity. So make one.

• New Node>Lighting>Specular>Blinn. Keep the settings at default.

Lets decide to make the bikini glossy - why not? So make a glossy node.

• New Node>Lighting>Specular>Glossy. Keep the settings at default.