Bio-Mechanical Tattoos: Bio-Mechanical tattoos, or as most call it Bio-Mech is a style of tattooing which depicts living robotics (human robotics). The most popular artist of whom has made this style of tattooing more popular, is illustrator H.R. Giger, of whom designed the creatures from the Alien movies. Majority of Bio-mechanical tattoos show flesh intermingling with machinery. Often times you will see bio-mechanical tattoos done in Grey wash, as it helps to find a flow between flesh tones, and the ink. However, if done properly, color can give a new intriguing look to bio-mech.
Grey wash (Black and gray tattoos): This style of tattooing was once believed to have been derived from prison tattoos, as getting your hand on colored ink was fairly difficult. It was soon brought fourth into mainstream tattooing, it was refined in the late 1970's, turning grey wash into the next big hit. Grey wash is usually used in a portrait tattoo, or anything that you are wishing to achieve a realistic effect. As said before, most of your Bio-mechanics are preformed with your grey wash technique. You can either purchase pre-made grey wash, or you can make your own by adding drops of water to a small amount of black.
Gothic style tattoos: Though there are many different types of "Goth." tattoos, such as skulls, or pents, or all the way to your more candy coated tattoos filled with bright colors, and ironic designs. Though the two styles are very different, they are one of the most predominant tattoo styles in the US. Chances are, if someone has a body suit, they will have at least one skull in the collection. The designs are endless, and not only "Goths" can get them.
Tribal tattoos: This form of tattoos has been practiced for centuries through a plethora of tattoo styles. Though most tribal tattoos are received by those who do not understand their background, simply for their striking appearance there is a thick history in tribal style tattoos. Historically, getting a tattoo was a right of passage, many girls were required to get facial tattoos before they were able to marry. The boy, would be considered un-fit to become a man if he couldn't handle the pain from the tattoo. Though tribal tattooing is common in America, it is hard to find an artist capable of completing the tattoo in one sitting. Between the need for straight, or flowing lines and the thick solid fill, it is a difficult tattoo to preform. It will take time and practice to get an even distribution of ink. I would suggest Kuro Sumi tribal black ink.