Folds in the skin

Some folds are obvious, such as those behind your ears and those forming your armpits.
But what about those on your hands and all over your body?

What do you call those?
Lines, wrinkles or folds?

«Lines» is a very general term.
Surely those are more than just lines, they have width and depth.
Lines have only one dimension.
Are they wrinkles?
Most people would say they are not, because wrinkles are characteristic of old and damaged skin.

Movement and folding

Flex your wrist several times and take a close look at the folding that this action creates.

Notice that some folds do not disappear completely when the articulation is straight.
The folds seem etched into your body because you have done this movement so frequently throughout your life.

They are folds

Close visual inspection only confirms that the skin is folded inwards.
You can trace their origin back to all the movements, expressions and positions you have taken, made or held.
Their path has tightened and solidified resulting in permanent folds.
The skin is bent so badly that it doubles up and that one part now lies on another part.
Epidermis over epidermis.

Similar folds

When I first found out about the folds, I thought that each human was folded differently, explaining the diversity of our looks.
Well, I was half wrong.
We do look different because of our folds, but these are comparable from one human to another.
Most folds are common to all humans while some are more specific.
The similarities are much greater than the differences.
We are all folded the same way.

Differences

Differences often lie in the size, angle and depth the same fold can take among humans.
Early in life, the shape of the skull is very important, the alignment of its parts particularly.
For example, the fold going from the side of the eye to the top of the ears is obviously affected by their respective positions.
Most of the distinctions come from how big the fold has become along its path.
This, in turn, depends on each individual's actions.
The way your nose is twisted, the way your eyes look, the way your eyebrows are formed, ... represent years of nose twitching, eye squinting or worried facial expressions.

Fold complexity

Folds are illustrated here as simple lines.
They are not so on your body.
Each fold is a complex monster with thousands of details.
They are made of coats, each one with a real life history.
A typical fold has hundreds of coats.
They are also far from straight.
Folds multiply, so you may find several parallel folds instead of one when you check on your body.

Early folds

Early folds are the deepest because they were in place before the end of your first year on this planet.
Most were created before your birth.
The folding occurring later in your life will modulate and refold these basic early folds.
They are beneath all other folds.
Still, some may be almost invisible.

Large folds, small folds

New folds keep on appearing all through your life.
They start out tiny, then deepen and widen with time.
In the palm of your hand, the largest, oldest folds are criss-crossed by smaller, newer ones.
But you're only seeing the surface.

Why are the folds so hard to see?

Two main reasons explain why your sight is deceived:

•All you see are the seams

Folds and their crossings keep on growing and become huge intra-cutaneous structures.
They do this by deepening and bringing more and more skin into them.
Their entire mass is beneath the surface and from the outside, all you can see is a simple seam.

Seam on a coat seen from outside

Same seam seen from inside

•It's all epidermis

Most of the folding is hard to distinguish because it is made of epidermis over epidermis.
A very tight seam, with no stitches, with perfect color matching is not easy to detect.
Furthermore, your skin coats the joint of each fold with free-standing epidermis cells, hiding the junction.
Even a microscope would only reveal patterns of epidermis cells.
To your ultra-sensitive nails and fingertips though, the folds are like mountains and canyons.

Fold types

•Vertical
•Horizontal
•Location specific
•Posture dependent
•Action dependent
•Expression dependent

Several folds follow a vertical-horizontal grid.