I reviewed the directions I have for cutting the one length haircut. When the sides, back and front are all the same length this is also called a square one length haircut.
One thing that distinguishes the differing directions is whether or not to use a center part or a natural part for the hair cut. From what I can tell using a center part is more useful for clients who want to move their part around or who always use a center part. If the hair is then parted to a side it will not be exactly a one length cut but the difference will be less than if a natural part had been used and then the part was moved to the other side.
Using a natural part is better for those who always use the same part. A natural part is determined by combing the hair straight back and then pushing the hair forward from the crown area and seeing where the part line develops. If a natural part is used it is taken back to the crown area where it is connected to a central part going from the crown to the hairline at the bottom of the nape. The connection is a slightly slanted part from the end of the natural part to the top of the back central part.
The other part used in the set up for this haircut goes from the top of the crown to behind the ears. I have seen this part starting any where from the apex to the bottom of the crown in different instructions. Most seem to start at the top of the crown and come down behind the ear but close to the ear. It has come down to the top middle of the ear for some directions. It divides the back of the head from the front.
Once these two parts are in place, the head is divided into four sections.
The next distinguishing mark for the different directions is whether or not the head is upright or tilted slightly forward to start the hair cut. Tilting the head slightly forward seems to let the hair in the final shape curl under slightly at the bottom instead of giving a totally flat surface at the bottom. Tilt of the head is decreased so the head is more upright the higher the sections/parts go up the head. This makes these sections have slightly longer hair than that from the lower sections.
Most directions start in the back two sections and near the bottom hairline on the neck. Directions are given to divide off a bottom section of hair approximately 1/2 to 1 inch in width . Some describe the part for this section as horizontal and some say it is slightly diagonally forward which means it starts in the middle and has a slight slope down as it goes toward the sides. I don't know the respective benefits of these parts. The slightly diagonal forward part may adjust the part to fit the curvature of the neck?
All the directions call for combing the hair to natural fall. They also all call for zero elevation or no lifting of the hair for cutting.
Natural fall means the hair falls down following the direction it is growing. In the back, the hair falls down the back of the head. On the sides, it falls down the side. The back and sides are separated at the back corners of the head. The back corners are found by putting a comb on the back of the head at the occipital bone. The comb is parallel to the floor and it is lying left to right on the back of the head. To find a corner on the left side, place a second comb on the left side of the head at the same level as the comb in back. Where the comb on the side intersects the comb in the back is where the corner is. Move straight in from the corner to the skull and this is where the corner of the head is. The corner on the right side is found the same way.
The corner is important because it tells you where to change your body position for cutting a one length haircut. Behind the corners in the back you stand behind the head. Then comb the hair straight down in the back. Once you reach the corner of the head, you move to the side of the head and comb the hair straight down on the side.
The length of the hair cut is determined in consultation with the client before the hair cut and after inspection of the clients scalp and growth patterns.
The hair is most frequently described as held in the wide teeth of the comb to secure it for cutting. One set of directions says to hold it against the skin with the side of the little finger to secure it. The cutting is done with you standing in front of the hair to be cut and with the comb parallel to the floor. The forearm and wrist holding the comb are also parallel to the floor as are the shears and the wrist-forearm holding the shears.
These sections can also be cut with a clipper. This is frequently a quicker way to cut the hair. The comb is held the same way as for the scissors. The hair is then cut by running the clipper along the comb or by pushing the clipper teeth into the comb parallel to the teeth of the comb. Going along the comb's length is faster because you don't have to repeatedly reposition the clipper.
The cutting action of the shears has been demonstrated as one long cut parallel to the comb and floor or as a series of little cuts along the length of the comb. I have not heard the benefits of the two different cutting methods.
When the bottom section is finished another horizontal parting is made 1/2 to 1 inch further up the nape and the hair is cut to follow the guide established in cutting the first section at the bottom of the nape. If the guide cannot be seen through the new section then this section should be done as a thinner section so that the guide can be clearly seen. Each back section can be cut alternating sides or one section can be cut all the way up to the part that divides the back of the head from the front before cutting the other side. Remember to change the body position as you go around the corner.
When all the hair in the back is finished a part is taken on a side that is horizontal to the floor and about 1/2 to 1 inch above the ear. This section contains some hair from the back section that has already been cut to act as a guide for cutting the side length. If you have started with the slightly diagonal forward parts in the back of the head, these can be continued to be used into the sides. On the sides the hair is combed into natural fall and cut parallel to the floor to match the length from the back of the head.
When cutting below the ears, comb the hair down and then tap the section above the ear either with the closed scissors or with the little finger of the hand holding the clipper. The tapping draws the hair up before it is cut so that there is extra length to make up for the ears sticking out.
Continue to take parts up the head until the natural part or center part is reached.
The other side is done in a like manner.
What I still don't understand:
1. Why use a natural part or a central part.
2. What is the explanation for horizontal parts as opposed to diagonal forward parts.
3. What is the purpose of the head tilt away from the cutting area. Is it only to give an undercut appearance to the cut?
4. What is the best method of cutting the perimeter. Is it better to cut in one long cut or to break it into several steps of cutting partially across the line?