I am so glad that I grew up in the era when tattoos were counterculture. I had no desire to deface my skin like this.
There are two issues which I have with tattoos and Judaism:
1) Tzniut - Modesty... When a person puts a image on their flesh they usually are seeking attention and want to show that skin and cause others to look. Both men and women need to be concerned with modesty and I find it very un-modest to draw attention to our skin.
2) Honoring Parents / Kibud AvHaIm - When a person is seen in public, especially a person who is attempting to be high class or be amongst people who did not come from trailer trash or low class people this person causes himself to be judged by others. Maybe this will change over time but I still look at women who have tattoos and think that they are prostitutes. Tattoos and immodest dress will cause me to label a woman as a slut because she is seeking attention for her body. This kind of judgment brings dishonor to parents.
People, and Jews especially, have a strong yetzer hara for what is forbidden. The more righteous a Jew tries to become the stronger his yetzer hara becomes. I am sure that most people who have tattoos have justified it in some way so they don't feel guilty for what they have done.
Regarding Tzniut:
http://ohr.edu/ask_db/ask_main.php/76/Q1/Sheli Berger wrote:
Dear Rabbi,
I understand the reason for married women covering their hair is modesty, yet today a lot of the sheitles (wigs) woman wear are nicer than their real hair. I think the wearing of make-up can be viewed in the same manner. It improves the person's appearance - doesn't this contradict the laws of modesty?
Dear Sheli Berger,
The Halachot of Tzniut - modesty - can be divided into two categories: relative and absolute.
The Halachot of Tzniut which are absolute are the minimal Torah standard. For example, the Talmud states that it is immodest for a man to listen to a woman sing. Similarly, a married woman should cover her hair, and all women should cover the thigh and upper arm. This means covering the elbow and knee - even when sitting.
The other aspect of Tzniut is the relative aspect, which changes based on societal standards. For example, in a place where the accepted style is to wear skirts down to the ankles - as was the style at the turn of the century - a mid-calf skirt would violate the laws of Tzniut.
This relative aspect of Tzniut applies only when the societal standard is more demanding than the Torah's minimal standard, like in the case of the long skirts. But if, for instance, mini-skirts are in vogue, the Torah standard would nevertheless require a woman to cover her knees.
What about wigs? Actually, there are Poskim who forbid wigs. Most people today however follow the opinion that wigs do indeed fulfill the Torah's requirement for a married woman to cover her hair. After all, her hair is covered, and if her wig is in keeping with the societal standards of modesty, then it is OK for her to wear it.
Certainly one reason for modesty is in order not to act in a way that is suggestive or alluring. But any behavior which stands out, as if to say "Look at me" is a lack of modesty. For instance, if mid-calf skirts are in style, someone who wears a floor length skirt, thinking she's being "more" modest, might actually be doing the opposite. By being different from everyone else, she actually calls attention to herself! Perhaps she wants to be noted for her pious behavior, but the result is a lack of Tzniut.
Tzniut is far more than a dress code. A person's attitude towards Tzniut reflects directly on his entire outlook, attitude, and approach to life. Is he interested in externals and what others think of him; or is he striving on an internal level, wondering what G-d thinks of him? If a person's main concern is to do what's right in G-d's eyes, he won't look at life as though it's one big fashion show, and he won't be crushed if he's not listed as one of People Magazine's "ten best dressed."
If a person chooses a wig called "Fantasma" or "Black Magic" this will be easily discernible in her general appearance and the way she carries herself. The cut, color and the way the wig is worn project an image. A modest style projects modesty; a flashy one, flash.
That having been said, it should be noted that Tzniut doesn't require a person to look like "Charlie Brown on Halloween." When the Talmudic Sage Abba Chilkiya would return to the city, his wife used to come out to greet him wearing nice clothes and jewelry. Her intentions were to look attractive for her husband. A person can, and should, always try to look presentable. The main thing is to keep in mind the verse "...what is it that Hashem asks of you, but to act justly, love kindness and to walk with Tzniut with Hashem your G-d."
Sources:
* Tractate Berachot 24a.
* Mishna Berura 75.
* Micah 6:8.