This is for haircuts that are started on the sides and then transitioned to the top before finishing the top. This assumes the sides have been cut and that the top of the sides will be the guide for the transition to the top of the head.
First a little on placing the boundaries of the parietal ridge before cutting the sides. This is important because it determines the guide for the transition from side to the top.
The parietal ridge is used to define how the sides will be cut. This defines how high or how low the guide for the transition to the top will be.
In the figure notice how the front hairline gives some ideas about the placement of the parts for the top and bottom of the parietal ridge. See how the upper and lower boundaries seem to bracket the pointed part of the hairline in the front.
Another method is to use your fingers to feel the parietal ridge as it slopes away from the center of the head starting about 1/2 inch above the ear attachment. About an inch above the level of the eyebrow you can feel the slope diminish as the surface starts to curve to the center of the head.
In placing the boundaries of the parietal ridge check both sides of the head and look at the back of the head.
In some people the parietal ridge is prominent and may need more hair to cover it and to smooth the head shape. In others it is nearly flat and may need some weight placement where it is expected so that the head looks more normal.
The prominence of the parietal ridge can vary from side to side so that a big parietal ridge on one side and a less prominent one on the other can be balanced with hair weight placement on the small side. The design can then make the head shape appear to be more symmetrical.
Figuring out how high and how low to define the parietal ridge for a specific hair cut is important. Many clients will not be able to say the ridge was poorly designed for them. They will be able to say they like it better when the layering on the side goes higher or stays lower. It seems that developing a good eye for the shape needed to perfect the head shape is a key. Once this is seen the placement of the parietal ridge boundaries becomes clearer. This in turns determines the guide for transitioning to the top.
A lower top parting along the parietal ridge allows for more weight build up above the part. A higher parting along the parietal ridge limits the weight build up above the part. With the lower parting there is more longer hair reaching the area above the parting.
The idea is not to physically identify the parietal ridge. The idea is to see where approximate boundaries can help you design for a more pleasing head shape.
For more weight along the corner between the top of the parietal ridge and the top of the head, longer hair will be cut in the transition to the top. For less weight, shorter hair lengths are used.
Decide if you are looking for a lot of weight, a moderate amount of weight, or less weight in this transition from the side to the top. A lot weight and length will be used if the sides are left long and if more hair is needed above the parietal ridge to give a good head shape there. Putting weight above the parietal ridge, gives this area a square look which some men prefer.
a. For a lot of weight, take sections parallel to and above the parietal ridge and comb them down to the guide cut at the top of the sides. By combing these sections down you preserve the length in them and you create weight.
b. For moderate weight, take sections parallel to the parietal ridge. Comb these sections straight out from the head at the level of the part. Comb the guide, cut at the top of the sides, up to the section and cut. By combing the section straight out, you effectively elevate the hair compared to what was done by combing the hair down to the guide. This shortens the length of the hair in the parallel section compared to the length left in a. above. This leaves less weight.
c. For even less weight in the transition, take sections from the center of the head to the top of the side. These sections are perpendicular to the parietal ridge.
Start behind the ear. Comb the section up and to the side of the head. Hold the hair with the fingers pointing down just behind the ear. The palm of the holding hand will be facing the scalp. Stand in back for cutting the right side and in front for cutting the left side if you are right handed. Cut to follow the head shape from the guide on the side to the top of the section.
The guide is found at the top of the side.
By combing the section in this way, the hair closer to the center of the head is elevated higher than the hair closer to the side of the head. When this section is cut, the hair closer to the center is shorter than in a. or b. above. This reduces the weight at the corner that runs above and parallel to the parietal ridge.
This type of sectioning allows a good range of weights in the transition from the top of the parietal ridge to the top of the head.
The most weight is placed there by combing the section from the center to the side so that the fingers holding the section are pulled all the way to the side of the head and they are vertical to the floor.
The least weight is by holding the section so it is cut to follow the head shape.
Intermediate weights in the transition area are done by first having the holding fingers hold the section vertical to the floor and then leaning the top of the section more to the center of the head. The further the top is leaned to the center the shorter the hair coming from the center will be. This will reduce the weight and allow for fine tuning of the design shape.
If the transition if started behind the ear, work forward and see if the front should be directed back in the transition area to leave length.
The back is transitioned the same way with the emphasis on weight placement while avoiding cutting whorls and cowlicks too short.
A lot of weight would be useful for squaring up a head with too much of a slant going from the side to the top.
Less weight could be helpful for rounding a head shape in the transition area. This might be helpful for a square head shape that does not need to have the squareness accentuated.
The emphasis in this note is on how much hair is left above the parietal ridge in transitioning from the side to the top. Once this is done, the amount of hair left on top of the head is determined. This will be done in a later post.