I have one on my left shoulder blade, it took almost 4 hours on one sitting and it starting hurting pretty good. It felt like he was in one spot the whole time and it's pretty damn big.
Mine started last spring when I got one for my oldest son, then one for my daughter, Now I went back last week to have my whole shoulder made into the universe but I have to sit Thursday for a couple of hours to finish it off. View attachment 7542