Essentially there are only two different sizes when it comes to tattoo needles. What are known as #12 diameter, and what are known as “bug-pins”, which are smaller in diameter than the #12’s. There are some variations available within each size, for instance the taper at the end of the needle may be long, or short, and the needle may be smooth or textured. Other than this all needles are more or less the same.
Basically we have “liners” and “shaders”. Liner needles are grouped together in various quantities in a round configuration, and are often tightened at the taper so that the points are very close together. Shader needles can also be configured in round patterns, as well as fanned out into what we call Magnums or “Mags”. There are other minor variations and some less common configurations that some tattooers use, but essentially this covers what is commonly used.
The individual needles are grouped together and soldered in place to form what is referred to as the “tattoo needle”, the needle is then soldered onto what is called a “needle bar”, which is just a length of stainless steel wire with a loop on the end which can be fitted to the part of the tattoo machine that creates the up and down motion. The unit as a whole is then cleaned, sterilized, and ready to use.