Hair Transplant and Density

[hairchallenged]

Hi folks,

 

Planning an HT sometime in the future, what is generally the acceptable density of grafts per cm2 to achieve an illusion of coverage? Due to the amount of 1/2/3/4 hair grafts available, would this vary as per the region being covered? Also, beard grafts I hear are thicker than scalp grafts, if that is the case would lets say 500 beard grafts appear denser than 500 scalp grafts for coverage? Thanks