Let’s flip this question around for a second.
Can anyone cite a Church document that specifically condemns tatooing? As has already been discussed, the levitical code condemns an awful lot of things, some of which were only binding on the Hebrews.
I probably cannot find a specific document PERMITTING the wearing of mixed fibers, but that does not mean, therefore, that the Church condemns it. Rather, I would say that the burden of proof lies upon the one claiming it is forbidden…
This is not to discount the fact that some people may have been taught as such by the nuns in school, but that in and of itself does not make it a moral pronouncement of the Church. I mean no disrespect to those heroic women, but some of the nuns also taught that Limbo was unquestionably where all unbaptized babies ended up, when in fact it was nothing more than a theory.
Peace,
Margaret (for the record, no tattoos!)

As to proof…The proof I give is it makes me toss my cookies to see it. ICK! Gross! Which means it breaks some commandment I am sure.
But there are guidelines which I have already posted.
Respect for Health and Bodily Integrity
The Fifth Commandment—“You shall not kill”—does not simply require respect for human life; it also compels Christians to respect the dignity of persons and to safeguard peace (see The Catechism of the Catholic Church, nos. 2258-2330). Respect for the dignity of persons includes, among other things, respect for the souls of others, for their health, and for their bodily integrity.
"Life and physical health," the Church teaches, “are precious gifts entrusted to us by God. We must take reasonable care of them, taking into account the needs of others and the common good” (Catechism, no. 2288). Prudence dictates that persons considering tattoos or body piercing research any health risks that may be involved. If a particular act of tattooing or body piercing entails a likely risk to health, it would be more or less sinful depending upon the gravity of the risk. If a particular act involves mutilation—if the act renders a bodily organ unable to perform its function—the act is immoral (Catechism, no. 2297).
Charity and Respect for the Souls of Others
Catholics must also consider the common good when they decide whether to be tattooed or have their bodies pierced. In certain instances—for example, in indigenous cultures in which tattooing is a rite of passage to adulthood—the common good practically demands that a person be tattooed.1 In the United States and other Western countries, however, considerations of the common good generally lead one to pause before being tattooed or having one’s body pierced.
The question of whether an act of tattooing or body piercing hinders a Catholic’s evangelizing mission leads to the broader question of whether such an act harms the souls of others. Tattoos whose words and images celebrate the demonic, are unchaste, or otherwise offend against charity are immoral.
Even if a tattoo’s words and images are not uncharitable in themselves, the act of obtaining a tattoo can be rendered immoral if done so with an evil intention—for example, in order to spite one’s parents or society (cf. Catechism, no. 1752).
Persons considering body piercing should also be aware of the implicit messages that the particular act of piercing conveys in a particular time and place. Some acts of body piercing can imply approval for the immoral homosexual lifestyle. Other acts of body piercing can imply active participation in, or a desire to participate in, other unchaste acts. In such cases, the acts of body piercing are immoral because they appear to manifest an approval of sin and thus scandalize others (cf. Catechism, no. 1868, 2284).
Questions to Consider
Catholics who are considering getting tattoos or having their bodies pierced may want to reflect on the following questions:
· Does this particular act of tattooing or body piercing involve a risk to my health?
· Would this act mutilate me—that is, would it inhibit the proper functioning of my skin or another organ of my body?
· Is the explicit message of my tattoo compatible with love of God and neighbor?
· Is the implicit message of my tattoo compatible with love of God and neighbor? Does it convey an implicitly unchaste message?
· Why do I want to get a tattoo or have my body pierced?
· If I am under the authority of my parents, would this act be an act of disobedience that would violate the Fourth Commandment?
· Would this particular act needlessly offend my family, friends, neighbors, and colleagues, and thus hinder my ability to lead others to Christ and His Church? Now this one would be yes…It offends me greatly. Like I said it makes me want to puke. And I am not being mean I am stating a fact. It makes me sick to my stomach.
· Can the expense involved be justified in light of the needs of my family, the Church, and the poor?