or people of Celtic heritage (Irish, Scots or Welsh), getting a Celtic design is often a way of expressing pride in ones heritage. Celtic tattooing is a reaffirming of affinity to the indigenous artistic style of our ancestors.
Most tattoo designs are inspired by the Irish Illuminated Manuscripts. One of these manuscripts is ‘The Book of Kells’, which is on display at the library of Trinity College in Dublin. The dates on these books are from a much later time than when Celtic tattooing is believed to have begun. Currently it is thought that tattooing for the Celts started around the time when Celtic stone and metalwork began.
Celtic history goes back thousands of years. The early Celts displayed their skills in Celtic art forms such as metal, jewelry and weapons.
The Romans regarded the Keltoi as fierce opponents. Celtic artwork and crosses can be found all over Ireland. They can also be found in other Celtic countries and in modern communities in the world.
Knot tattoos are usually made with Knotwork. They are usually made with no beginning and no end. A knot with no beginning or end symbolizes the never-ending cycle of death and rebirth.
Knots that are pure are unending unless they end with a zoomorphic design (feet, heads, or tails) or a spiral. Un-pure Knotwork ends with a broken, ended, strand or does not connect back to its origional band.
Zoomorphic tattoo designs (or designs in general) are very similar in construction to normal knotwork. Zoomorphic tattoo designs, however, use animal heads, legs, tails, body, or feet.
Spiral designs are designs that are formed out of lines which spiral and twirl in a parallell, usually uniform manor.
Source : http://celtic-tattoo.net/default.aspx