What type of inks were used if any? How has the process changed? Where do we see the first evidence of people being tattooed? Was branding a common form of tattooing?
Well, the most obvious change is from hand tapped- or poked- tattoos to the use of a modern machine. Cut tattoos, referenced in the same entry, are a bit hit-and-miss (it's tricky to cut to the right depth and get the ink to stay put-blood washes it out-although see the link to Otzi below). As to the earliest evidence, here's a couple of tattooed ancients- Otzi, tattooed with charcoal 5300 years old and the Ice Princess, 2500 years old
hi! there's lots of room for more specifics, but you may be interested in these threads
Origin / early examples
Origin of Tattoos - South American mummies, Ötzi
When did the first tattoos start to appear in history? Who came up with the idea of putting ink (or other substances) into skin? - South American mummies, Ötzi
I read that in its early days in Europe, tattooing was popular among the rich and powerful, including members of royal families. To what extent is this true? - South Pacific, Europe
Are there any indigenous people that actually use tattoos? - South Pacific, Americas
Tattoos in the Song Dynasty - Song Dynasty China
What would have the tattoos of the real Norse looked like? - Norse
Techniques / materials used
The Inuit used to use soot from their lamps and a needle and thread to tattoo them selves.