This is my drawing for my token for my tiefling artificer, Curiosity, used for Rime of the Frost Maiden.

I spent most of yesterday drawing this, mostly constantly, starting around 11am and stopping at 8pm for the session, and I spent about an hour on thursday too, so, removing the time I spent doing other things (eg eating), I'd say this was probably an 8 hour drawing. Maybe a little more than that, but 8 hours sounds about right to me.