Transitioning decals with masks on a character

Wondering if anyone knows of a way to transition between textures.

Ultimately I would like to fade decals on a character. This could be tattoos, bruises or changing lipstick colour on a character.

Answering my own question…

2 ways

first

http://wiki.unity3d.com/index.php/Blend_2_Textures

this is good reading

I needed a more complex shader so I used
Substance Designer using these techniques