This is a quote from the above link. I find the second statement quite amusing as the decorated by the lord statement refers so spiritual understanding and a good spirit kind of adornment, not physical adornment. Physical adornments such as jewellery, tattoos, dying hair, make up etc are not considered part of the spiritual path-they are mere distractions! In the case of the tattoo, I would liken it to the big khanda's displayed in the posh cars of gangster boys trying to make a statement (except those can be removed)!!A. I don't believe there is anything directly written against or in favour of tattoos in the Sikh scriptures. Tattoos can be grouped with "extreme make-up" which the Guru calls "decorations" and I ask you to read the article Guru Granth Sahib on adornment.
The Guru tells us that "without the remembrance of the Lord, the 'sheegar' (decorations) will bring no happiness or comfort".
On the other hand, the Guru says that if one remembers the Lord all the time (ie: "within whose home the Husband Lord abides"), then he or she will be "totally adorned and decorated" by the Lord. So if you live according to the Waheguru's hukam, then you may decorate yourself as you like.