How long does it take to tattoo the forearm?

It's a few hours fast, and more than ten hours slow (two or three times is enough). Depending on the complexity of the pattern, different tattoo artists can make the same picture at different speeds.

There is no absolute relationship between speed and tattoo effect. It takes a third-rate artist 20 hours to make a thing, but the effect is still not as good as that of a first-rate tattoo artist 5 hours. ...