This is a very interesting question. There are two important limits for the density of the recepient sites. First, if you go over the number of 35 or 40 recepient sites per cm² there is a risk of bad regrow. There is also very often the risk that the grafts collapse because the density is not reasonnable. Second, the patients who asked for a high density forget that the number of grafts, even if it is an important number, must be spread on a surface big enough to make a satisfying result. If we increase too much the density, the surface to cover will decrease. It is better to think about it in this way. What is the best way to spread in density and on the surface the number of grafts reached? The key to obtain a good hair transplant is more the distribution’s strategy then the quest for maximal density.