Within  the category of Celtic designs can be added to the Viking design,  German wattle due to similarities with Celtic in its form  and symbolism.  
This style is  characterized by several types of two-dimensional designs of interwoven  strips of infinite cyclic or spiral shape and ornamentation in the form  of a labyrinth. In the past it was used  in various places, from the engraving, which are decorated with weapons  and tools to the churches and cathedrals. The basic symbolism of Celtic and Viking designs is an endless cycle of birth, life and death. In addition to the basic symbolism can show some kind of event formed with human and animal figures. They can also describe a complex story in a way that style screened on medieval tapestry.  
The  Celtic tattoo is often used as a complement to the fantasy style and tattoos  of religious themes, but often tattooed as a whole in itself.