Tutorial 2. Pattern Calculation before Cutting (Continued).
Tatyana Kozorovitskaya’s Formula.
I want to achieve the same configuration of the side seam at the front and at the back of my dress!
I always use the formula I derived about 7-8 years ago for this purpose. It has never let me down ever since!
I recommend you having this picture above your cutting table:
Kate | Pattern | Front | Back | BM | |
---|---|---|---|---|---|
Waistline | a | b | e | ||
Stomach | c | d | X | Y | e |
So, the sum of unknown variables X + Y that I need to find should equal the difference between client’s measurement (c) and pattern measurement (d) divided in half. If there are any alterations along the bust middle (e) then this value should also be accounted for: d + 2e.
The difference between the unknown variables X - Y should equal the difference between the gain at the front (a) and the back (b) taken from the previous table line, i.e. the value a – b.
It is much easier when applied than when explained in word.
So, here is my particular case.
The final table of re-calculation for the standard pattern (Table 1):
Kate | Pattern | BM | Front | Back | |
---|---|---|---|---|---|
Bust front | 18.1 | 19.3 | 0.4 | -0.2 | |
Un.B. front | 14.6 | 15.7 | 0.4 | -0.2 | |
BC | 33.5 | 36.6 | 0.4 | -0.2 | -1 |
UBC | 29.1 | 33.1 | 0.4 | -0.2 | -1.4 |
WC | 28 | 30.3 | 0.4 | -0.2 | -0.6 |
S | 35.8 (4.7) | 37.4 | 0.4 | -0.2 | -0.2 |
HC | 37.8 | 39.4 | 0.4 | -0.2 | -0.2 |
Clip | 3.5 2 2.4 | 4.2 3.5 2.9 | -0.7 -1.6 -0.5 | ||
BM | 7.1 | 7.9 | 0.4 | ||
SL | 7.5 | 7.9 | -0.4 | -0.4 |
I have removed 0.2 inches along the bust-line at the front and 1 inch along the bust-line at the back.
Now I need to even out the side seam for the under-bust line. There is quite a significant dispersion of values here. I need to remove 0.2 inches at the front and 1.4 inches at the back.
Therefore the difference between the values along the bust-line and the under-bust line is as follows:
- at the front: 0.2” – 0.2” = 0”;
- at the back: 1”– 1.4” = -0.4”.
This means that side seams of the front and back at the area between the bust-line and the under-bust line are going to have unlike inclinations, i.e. diverse configurations. It will then be very hard to match these pieces and join them together. Inclinations of these side seams need to be evened out.
In other words, I need to calculate suitable values of “x” and “y” instead of the values of -0.4” and -1.4” along the under-bust line (line 5) to make the side seams of the front and back have the same inclination or an identical configuration.
I even out side seams using my formula:
First of all I draw a separate table:
Kate | Pattern | Front | Back | BM | |
---|---|---|---|---|---|
BC | a | b | e | ||
UBC | c | d | X | Y | e |
I re-write all existing values from Table 1 into the new one (Table 2):
Kate | Pattern | Front | Back | BM | |
---|---|---|---|---|---|
BC | -0.2 | -1 | -0.4 | ||
UBC | 29.1 | 33.1 | X | Y | -0.4 |
Along bust-line:
- front – minus 0.2” (a);
- back – minus 1” (b);
- bust middle – minus 0.4” (e).
All these values have been calculated previously.
Along under-bust line:
- variables X and Y are gain values along the side seams of the front and back;
- bust middle – minus 0.5” (e);
- under-bust circumference after Kate’s measurements and after the pattern correspondingly: 29.1” (c) and 33.1” (d).
As a next step I substitute existing values from Table 2 into the formula:
It is very important to substitute a gain value with a minus sign if it is negative and with a plus sign if it’s positive.
I have got a most basic system of 2 equations that is solved by the substitution method.
From the second equation of the system
I find that
I substitute the value of (
) instead of
into the first equation of the system:
I substitute this value into the equation:
And now I substitute the determined values instead of values
and
(Table 3):
Kate | Pattern | Front | Back | BM | |
---|---|---|---|---|---|
BC | -0.2 | -1 | -0.4 | ||
UBC | 29.1 | 33.1 | -0.4 | -1.2 | -0.4 |
And so I have evened out the side seam for the under-bust line.
Now I need to even out the side seam along the waistline.
I go down by a line in Table 1.
I draw an additional table and substitute determined values from Tables 1 and 3 (Table 4):
Kate | Pattern | Front | Back | BM | |
---|---|---|---|---|---|
UBC | -0.4 | -1.2 | -0.4 | ||
WC | 28 | 30.3 | X | Y | -0.4 |
The calculation is entirely the same.
And again I use my formula of side seam adjustment:
I substitute the determined values from Table 4:
I determine the values of
:
And now I insert the determined values into Table 4 instead of
and
(Table 5):
Kate | Pattern | Front | Back | BM | |
---|---|---|---|---|---|
UBC | -0.4 | -1.2 | -0.4 | ||
WC | 28 | 30.3 | 0 | -0.8 | -0.4 |
So I have evened out the side seam along the waistline.
Now I need to even out the side seam along the line of the stomach.
I go down by a line in Table 1.
I draw an additional table substituting determined values from Tables 1 and 5 (Table 6):
Kate | Pattern | Front | Back | BM | |
---|---|---|---|---|---|
WC | 0 | -0.8 | -0.4 | ||
S | 35.8 | 37.4 | X | Y | -0.4 |
The calculation is entirely the same.
And again I use my formula of side seam adjustment:
I substitute the determined values from Table 4:
I calculate
:
Now I substitute the determined values into Table 6 replacing
and
(Table 7):
Kate | Pattern | Front | Back | BM | |
---|---|---|---|---|---|
WC | 0 | -0.8 | -0.4 | ||
S | 35.8 | 37.4 | -0.2 | -0.6 | -0.4 |
As a result I have evened out the side seam along the line of the stomach.
Now I need to even out the side seam along the hip line.
I go down by another line in Table 1.
I draw an additional table substituting the determined values from Tables 1 and 7 (Table 8):
Kate | Pattern | Front | Back | BM | |
---|---|---|---|---|---|
S | 0.2 | -0.6 | -0.4 | ||
HC | 37.8 | 39.4 | X | Y | -0.4 |
The calculation is entirely the same.
And again I use my formula for side seam adjustment:
I substitute determined values from Table 4:
I determine values
:
Now I substitute the determined values into Table 8 replacing
and
(Table 9):
Kate | Pattern | Front | Back | BM | |
---|---|---|---|---|---|
S | 0.2 | -0.6 | -0.4 | ||
HC | 37.8 | 39.4 | 0.2 | -0.6 | -0.4 |
So, I have evened out the side seam along the hip line.
This way I have evened out the side seams along the front and back in all relevant areas of the dress starting from the bust-line and finishing at the hip line.
All these re-calculated gain values from Tables 3, 5, 7 and 9 should be written down into Table 1.
Final table of standard pattern re-calculations with side seam adjustments accounted for (new values are marked with blue) (Table 10):
Kate | Pattern | BM | Front | Back | |
---|---|---|---|---|---|
Bust front | 18.1 | 19.3 | -0.4 | -0.2 | |
Un.B. front | 14.6 | 15.7 | -0.4 | -0.2 | |
BC | 33.5 | 36.6 | -0.4 | -0.2 | -1 |
UBC | 29.1 | 33.1 | -0.4 | -0.4 | -1.2 |
WC | 28 | 30.3 | -0.4 | 0 | -0.8 |
S | 35.8 (4.7) | 37.4 | -0.4 | -0.2 | -0.6 |
HC | 37.8 | 39.4 | -0.4 | -0.2 | -0.6 |
Clip | 3.5 2 2.4 | 4.2 3.5 2.9 | -0.7 -1.6 -0.5 | ||
BM | 7.1 | 7.9 | -0.4 | ||
SL | 7.5 | 7.9 | -0.4 | -0.4 |
It is necessary to check everything! Do not start cutting without checking first!
I check every line of the table containing new values.
The point of such checking is the following: the value of a standard pattern measurement + all calculated gains (their values are multiplied by 2) = client’s measurements.
Along bust-line: 36.6 – 0.8 – 0.4 - 2 = 33.4.
Along under-bust line: 33.1 – 0.8 – 0.8 - 2.4 = 29.1.
Along waistline: 30.3 – 0.8 – 0 - 1.6 = 27.9.
Along stomach: 37.4 – 0.8 + 0.4 – 1.2 = 35.8.
Along hips: 39.4 – 0.8 + 0.4 – 1.2 = 37.8.
I am used to working with full circumferences. If you find it more comfortable working with semi-circumferences, then you should just write down semi-circumference values into the table and then you don’t need to multiply by 2 when checking gain values. It doesn’t affect the point of this method.
Having checked everything I am now confident that all calculations are made correctly!
Now I am going to schematically draw the location of the new side seam on the front and back.
All values are taken from Table 10.
Side seam at the front:
- I reduce the pattern by 0.2” along the bust-line;
- I reduce the pattern by 0.4” along the under-bust line;
- there are no alterations along the waistline (-0);
- I expand the pattern by 0.2” along the stomach;
- I expand the pattern by 0.2” along the hip.
Side seam at the back:
- I reduce the pattern by 1” along the bust-line;
- I reduce the pattern by 1.2” along the under-bust line;
- I reduce the pattern by 0.8” along the waistline;
- I reduce the pattern by 0.6” along the stomach;
- I reduce the pattern by 0.6” along the hip.
That is what the side seam of the front and back looks like (schematically):
You can notice even from this schematic drawing that the side seams are symmetrical and have the same configuration.
Let me take the area of the side seam between the under-bust line and the waistline as an example.
The difference of gain values between these lines is:
- at the front: 0.4” – 0” = 0.4”;
- at the back: 1.2” – 0.8” = 0.4”.
Therefore the side seams of the front and back in the area between the under-bust line and waistline are going to have the same inclination, i.e. configuration. It is going to be very easy to match and join these pieces together. I have evened out inclinations of the side seams.
There is the same result after checking other areas of the pattern: the side seams of the front and back have the same inclination.
Looking ahead, I would like to demonstrate you how correct my calculations and my formula really are.
In these pictures you can see the result of the first and only fit test of this sewn dress:
See for yourself how well the dress fits!
There are no folds, no creases and the side seams are perfectly in place!
I hope I have managed to prove the correctness of my calculations and showed you that you can and actually even should use my formula!