HAIR TRANSPLANT FORUM

The theory behind 41% has to do the the percolation theory. in other words, if you do not want light to percolate through to the sclap, thus reflecting two colors (the color of your hair and the color of your skin) you must occupy 41% of the surface area.
in theory, you could take a single hair, wrap it around the head hundreds or thousands of times and you would acheive coverage. This is a principal that Donald Trump among others use. they sweep hair from the back of the head up over the bald or thin areas to the front and then sweep it back over the bald area for a second time. In this way the same hairs cover the area of hair loss twice and give the illusion of fullness or hair restoration.
The normal scalp has hair in only 10% of the total surface area. This 10% is able to achieve the illusion of full coverage provided that it grows to a specified length. When the head is shaved as in milatary recruits, their are two contrasts - hair and skin. when the hair grows slightly longer the suface area or volume of hair exceeds the percolation threshold and we no longer see the skin color.
the volume of every single hair shaft on your head is equal the product of its radius squared X Pi X Length of the hair. the width of the hair is more important than either the length since its radius is expotentially important to the illusion of coverage. The total volume of hair is equal to the sum of all the individual hair shafts volume. I called this product hair mass in 1998. Every person has their own individual hair mass. Hair mass is not dependent on the orientation of the incision as you can see. the longer you grow your hair, the more hair volume and hair mass you have. you can do little about diameter except to use fillers such as toppik.
we also us a volumizing hair gel in our office that allows tiny particles to stick to the hair shafts and make them look thicker.
if a person has a coarser hair, it will cover better due to its increased radius. curl or wave adds length to each hair in the critical area or the area of hair loss. this is how these factors contribute to coverage.
it is much easier for a person to restore their illusion of coverage if they have coarse hair. it is much harder when they have fine hair. it takes far more grafts to create this illusion of fullness if you have fine hair.
you do not always need to restore your hair to 41% of the original density to have the illusion of coverage and sometimes you may need to create more than 41% of the original density to have the illusion of fullness. you can also use creative hair styles to effect an illusion of fullnes by doing hair transplants that leave you with a density in many areas of he scalp that is far less than 41% of the origianl density.
i came up with the 41% of the original density in talking about the shaved head. if you want to shave your head after a hair transplant, it may be that 41% of the original follicular density may give an appearance of a full head of hair with your head shaved. This is the less is more phenomenon. if you occupy 41% of the original sites when you had a full head of hair, you may look normal with your head shaved. less than this density may leave you looking thicker on the back and side and thinner on the top. it is currently a theory though and one we hope to put into practice over time.