Art is an expression of feelings, thoughts, culture, and life in general. Most of the time its subjective rather than objective.
I've always thought that art is an "expression".. meaning something that is made to be external from oneself. Wearing of various accessories is an art, and so is choosing your own clothes. The external appearance that you display to the public, is your form of art. Even so, application of make up is an art. There are many ways of applying make up and it can drastically change how a person may perceive you through these self applied art. But, this is a more conservative view.
For different cultures, the color of the skin is an expression of art. It is only a sad fact that some black or dark colored skin tend to look themselves down due to racism. I believe black is beautiful. 
The skin is the largest vandal board of the body. If anyone is familiar with the modern-day-internet-era shoutout, then maybe, tattoos are the shoutouts of the past. Do you agree??
In the past, only people who care less about their body get tattoos. This is why only convicts and prisoners get at least one. (Or sometimes to kill boredom?? 
) But now, tattoos have a steady trend and supporters already. I even know of somebody who always fascinates himself by looking at tribal tattoos.
Personally, tribal tattoos are cooler than any other category. Animal tattoos are already common.. I mean, all tigers look alike, so do all eagles, etc. Tribal tattoos are different. Its more personalized and looks cool. 
But you know, if these designs where pendants on a necklace or the engraves of a ring.. hey, then I think I'd consider buying. Hehehe.. 