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This article is aimed at the more experienced and will require some knowledge of pattern making. It focuses on patterns such as 1-piece swimwear, bodysuitsOther pattern adaptations are possible, but will be covered in other articles.
This article looks at a number of different concepts to help you identify whether you need to adapt :
- the vertical pattern: upper torso and crotch
- the position of the bottom of the trousers/between the legs.
The content of the article is dense ... feel free to pause, reread it, ... test it.
These are basic concepts to be understood when designing stretch garments (with the notion of tension lines).
Table of measurements
Before talking about fitting, you need to know the table of measurements used to design a pattern, and this applies whatever the garment to be fitted.
For all garments such as swimwear, bodysuits, knickers, etc., this is essential. The garment is designed with one or more reduction rates for a snug fit.
Below is the table of measurements used to design our patterns (the main measurements needed to understand this article).
Vertical adjustment of the upper torso
To do this, we are going to look at the :
- Waist-to-chest distance
How much will I have to increase or reduce the verticality of the upper torso?
Compare the distance measured with that listed in the table of data used to design the Idonim patterns.
If the distance measured is greater than that on the size chart -> the vertical pattern between the waist line and the bust line will have to be increased.
If the measured distance is less than the distance on the size chart -> the pattern will have to be shortened vertically between the waist line and the bust line.
How can I shorten or increase the verticality of my upper torso?
increase
reduction
Vertical adjustment of crotch
To do this, we are going to look at 2 other measures:
- Waist to hip distance
- the distance between the waistline and the narrowest point of the crotch
The distance between the waist and the hips (A) is often difficult to measure for many of us. Yes, where is the hip line? This is often a source of error. We will consider that the hip line is the line or the circumference is the largest (e.g. passage to the tip of the buttocks).
In our case we are also interested in the distance between the waist line and the narrowest point of the crotch (B). This distance should be measured with a tape measure held vertically. Do not place the tape measure along your body to avoid bending it! If necessary, ask for help. To do this, sit down on a chair or a flat, hard surface.
How much will I have to increase or decrease the pattern in verticality?
It is necessary to know the data/measures used in the design of the pattern. This is where the story gets complicated. Not all the data and specifications are published with the commercially available patterns.
I'll make it short, you'll have to make a rule of three between the measurements you've taken and the measurements of the pattern at your size.
Calculation to be made :
waist - hips table reference - (B/A x waist-hip table reference)
The result is positive -> the pattern will have to be shortened in verticality
The result is negative -> the vertical pattern will have to be increased by the same amount
The distance to be increased or decreased will be distribute vertically at the level of the crotch.
How can I shorten or increase the verticality of my crotch?
If you need to increase or decrease the verticality, you will have to retrace the area of the bottom of the breeches, taking care to respect the width of the gusset at the narrowest point (inflection point between the front and the back) but also not to reduce or increase the width of the bottom of the breeches at its extremities
Adjusting the position of the gusset
This is a very important concept for me. It is important to know and understand. It will allow you to adjust all clothes such as: panties, swimming costumes, bodysuits, leggings, shorts, ...
If there is one thing to remember, it is what follows.
Its position is linked to your morphology: retroversion or anteversion of the pelvis.
examples:
- anteversion -> tilting of the anterior pelvis - arched back
- retroversion -> tilting of the posterior pelvis - back not arched
*The notion of arched back does not take into account the shape of the buttocks (flat, voluminous, ...) which will also impact on the fit of a pair of panties, ... but there it is the shape of the panties or bikini that will mainly impact on the fit of the garment. This topic will be covered in another article.
How to quantify anteversion and retroversion?
The most complex thing is to determine how much retroversion or anteversion there is.
The "simplest" version is to estimate the angle formed by a line passing through the tip of the illiac bone and the symphysis pubis, as shown below.
To do this, it is essential to position yourself correctly in profile. Do not hesitate to touch in order to identify the position of the bony points (it is important to base yourself on the position of the pelvis and not the stomach).
In retroversion, the angle can be between 0 and 10 degrees.
In anteversion, the angle may be between 0 and 22 degrees.
How do you modify a pattern according to the degree of inclination of the pelvis?
The example below is valid for panties or bikinis
I move the inflection point of the crotch 2 cm for every 15 degrees of inclination and so on. The same applies to the forward and backward tilt of the pelvis.
Just think:
- anteversion -> moving the bottom of the trousers towards the front (reduces the length of the front and increases the back)
- retroversion -> moving the bottom of the trousers towards the back (reduces the back length and increases the front).
You will then have to retrace the area of the bottom of the panties, taking care to respect the width of the gusset at the narrowest point (point of inflection between the front and the back) but also not to reduce or increase the width of the bottom of the panties at its extremities.
What's next? But only for a 2-room apartment!
-On the front: open (or close for the backward inclination) the front of the panties / or swimming costume bottoms - if the pelvic inclination is 10° open or close 5° on each side respectively.
-On the back: slightly widen or reduce the width of the breeches. For example, in the case of an anterior tilt, the tilt of the pelvis causes the lateral sides of the buttocks to move outwards.
Conclusion
If you need to reduce or increase the length of your torso, make this change first.
The most difficult thing about the crotch is often to determine how the increase/decrease will be distributed between the vertical correction and the position of the inflection point. But when you look closely, its position is essential.
If you need to adjust the pattern for this reason, adjust the position of the inflection point first and only then the vertical adjustment of the crotch.