| Fold crossing theory |
| A single fold is a theoretical concept. On your body, any fold will eventually meet another fold. |
| Fold crossing evolution |
First, let’s separate the two folds of the crossing and call them Fold A and Fold B.


Very early in your life, Fold A and Fold B started meeting when you would do something.
At first, they probably did not meet at the exact same place every time.
As their paths became etched into your skin, due to specific epidermis formation, so did the position of their crossing point.
The walls of both folds now crash into each other every time you do the same movement.
At the crossing point, the skin is badly and continuously deformed.
All this generates lots of heat.

The heat is worse in the center and at the four corners.
Epidermis formation will come to the rescue of the poor crossing in order to prevent breakage or puncture.
One by one, coats of protective epidermis cover the crossing's center.
This action solidifies the skin of this mistreated region, but locks the crossing into place.
Since folds A and B are already grooves, not mounds, the fold crossing is a hole.

As it evolves and fixates, it grows deeper and deeper below the surface of your skin.
The chimney starts forming.
The very top of the fold crossing keeps on refolding.
As time passes and your actions challenge it again and again, the top edge of the crossing adds new coats of locking epidermis to protect itself.
This brings new unfolded skin, next to the opening, into the chimney.
Sometimes, this relentless refolding forms a mound or
agglomeration above the skin's surface.
They become jumbled messes of skin,
We notice the darker ones, but generally there is little color change. They could also be paler.
Epidermis formation often places a hard cover on the whole mass.
The crossings build their chimney coat by coat, each coat being caused by your movements, just like the folds.
But the crossings see much more action than their adjoining folds, the tensions from the folds being relayed to the crossings.

So crossings develop about ten times more coats than their folds.
Fold crossing become huge.
As the fold crossings on your body deepen, their connected folds also increase their depth.
This has the effect of thickening your skin gradually.
It is accompanied by a steady loss of sensitivity.
When grooming, your nails remove the coats of epidermis cells one by one.
Since these coats have been created in time one above the other, you are always grooming the most recent coat.

Every coat corresponds to some actions you have done in the past.
Removing them is like reliving your life backwards, counter-clockwise.
One could compare the task to unbuilding a house. You can't start with the foundations; you have to remove what is above, coat by coat.
Most fold crossings are almost invisible to the naked eye.
They can be seen easily on your palm and soles, so you can observe a variety of styles with their branches meeting at every possible angle.


Some crossings are quite deep with redness visible in their center.
Some crossings grow in size while others simply tighten, most will do both.
At some point, the whole structure of the crossing may collapse and become part of a new, bigger one.
It can roll over itself.
A crossing can link with adjacent ones.
It can protect itself with a very hard cover.
A lock is a draping of the skin on one side of a fold crossing.

Like an accordion or a hand fan, they are made of tens, sometimes hundreds, of small folds.
| The grid of folds |
Your skin’s natural horizontal and vertical folding tendency ends up giving a grid of folds and crossings.

Please note that the folds are not equally spaced like in the illustration.
In reality, the grid is variably spaced and complexifying, adding more folds (often diagonal) between existing ones as needs grow.
This grid adds new strength to your skin acting like a flexible skeleton inside of it.
It brings relief to large sections of skin between the folds.
The damaging pulling forces from your actions now travel down the branches of the folds up to the ever-growing crossings.

Tensions at one crossing are relayed to all the crossings in its vicinity.

The grid of fold crossings has several disadvantages;
•It greatly reduces the skin's flexibility and elasticity.
•On the face, expressivity and beauty are diminished.
•It interconnects problem areas. Doing one movement now affects regions further and further away.
•...
Because the size of your body has increased since your youth, the grid has tightened.
It is deepening into your flesh.
The folds and crossings multiply, enlarge and squeeze your skin still more.
This reduces your capacity to move, it makes anything you do more painful as you get older.