It turns out you can do this with a shape and have the ref set to ‘paper’. The problem with this solution is there is no tooltip for shapes. One recommendation here is to have associated scatter points with tooltips. If I were to do this, I would want the point on the “edge” of the graph. If I could accomplish this, I wouldn’t need the shape in the first place, I could just create the Scatter line to the edge of the graph area.