Have a look at the thread on this page `` Lower density = less knots ?`` ... I left a reply there yesterday regarding densities...might be of interest to you. Generally my own feeling is and I agree with Xeon005 there, the longer hair calls for a bit lighter density or it will really look like a rug ..... long, dense hair would look a bit like a mop ! I think that last pic there is so realistic as the guy has [ I reckon ]specified a lighter density just there at the front and then `stepped`it up further back ..it looks very very realistic to the eye because it`s `natural`...we `expect` thinner hair at the front edges and temple areas on people in general......a sure give-away as a wearer, is to have the exact density all over.....the eye will register it and tell the viewer that ``something is not right here``. Paul.