Let's talk about swimming costume patterns.

Summer is just around the corner, the sun is shining, it's time for a holiday! Do you want to wear your handmade swimming costume on the beach?

This article is dedicated to patterns to make your own swimming costume: to give you some notions to talk about when it comes to swimming costume patterns. They are interesting to know before you start.

Received idea?

Some people will tell you that you can re-use lingerie patterns to make your swimming costume BUT ... That "s not a good idea...

Swimwear patterns are generally of a specific design:

• The discount rate is higher - see textiles used. 12% to 15% for a swimming costume / 8% for a bodysuit or dancewear.
• The assembly techniques are more varied, the use of a lining has to be taken into account, the elastics and fabrics are also different.
• The styles and shapes are different compared to traditional lingerie.

Remember that a swimming costume is to be worn wet. You will be swimming, moving, .... And that's a game changer too!

Let's talk about the technical side

The design of swimwear is more technical than traditional lingerie:
3 criteria are particularly important:

• The rate of reduction
• Tensions: it is important to identify where the tension lines run in the swimming costume. There should be no creases. The swimming costume must not yawn, it must be perfectly flat and hold
• It must be adapted to your morphology and measurements

In the specific case where a pattern is designed for a similar elasticity to the fabrics you are going to use for your swimming costume, then in this case you can use your lingerie pattern. However, the fabrics, elastics and assembly techniques will be different and the pattern will have to be modified (sewing values, ...).

The rate of reduction

When designing a stretch fabric garment the aim is to create a pattern where the tensions are even in all directions. If there is one thing you must remember, it is this: if the tensions are not evenly distributed, creases will appear.

Here we come to the notion of stretch: stretch 4 directions (US) (or 2 directions in FR/EU) are to be considered: the direction of the height and the direction of the width of the shirt.

To ensure that the swimming costume 'sticks and sits' on the body, a reduction rate must be applied to the pattern (as opposed to the ease rate for a traditional garment without stretch).

The reduction rate is the coefficient applied to your measurements to create the pattern. For example, for a chest measurement of 90cm and a reduction rate of 12% -> the size corresponding to the chest measurement of the pattern will be 90×88/100, i.e. 79.2%.

In general, when I design my swimwear, I only apply a reduction in width (around the body) and not in height - unless I have a specific pattern.

Why?

• linked to the characteristics of the textiles used and the model. When you apply tension to a stretch fabric (when you stretch it) the fabric will naturally shrink in the 90° direction. The fabric will compensate for the tension you apply in one direction by reducing the tension in the other direction. This phenomenon is linked to the type of fabric used. Do a test. Depending on the pattern, a reduction rate may be applied vertically, but generally not to the whole pattern. But we'll come back to this point.
• allow the body to move / comfort / keep some ease.
• Create a pattern best suited to the market. It's more interesting to create a pattern based on chest size, waist size, hip size, etc., i.e. based on horizontal data. Stature has a significant impact on swimming costume length, not waist size, ....

For the design of swimwear I generally apply a reduction rate of approx. 12% horizontally and 0% vertically - valid for a 200g/m2 fabric PA80% and EA20%. Valid for a large part of the fabrics used in swimwear with a traditional type of lining (foam fabric)

In general, the more reduction you apply horizontally, the less you have to reduce the pattern vertically.

The pattern is therefore given for a given stature. If you are taller or shorter, the pattern can easily be modified. But be careful not to do anything ... the result could be catastrophic and you could end up with an uncomfortable swimming costume. See the tips and tricks section at the end of the article.

Tensions

To understand where the tension in the swimming costume will go, it is important to also understand how the swimming costume will behave when you move. The suit will always move where the tension is lowest!

In short, you have to concentrate and understand where the power lines run.

For example:

• around the neck
• in the line of the ramps
• around the waist

If the tensions are not uniform, you will see folds appear or the bikini will not fit snugly against the bust or conversely will be too "tight"... The tensions can be adjusted by increasing or reducing the lengths in certain places.

When two lines meet, it is called an anchor point - it is a point of stability.

These are quite complex/abstract concepts for some, but empirically understandable. I think that some illustrated examples could help you. If you are interested, please let me know, it could be a topic in its own right ...

Morphology

Choose a pattern that suits your body shape, comfort and aesthetic. There are more and more patterns from inclusive brands that offer a wider and wider choice of patterns.

Developing the same pattern from size 32 to 56 using linear grading rules is going too fast! The more you go up a size, the more the pattern will be affected by morphological characteristics. So you're going to have to adapt it: this can be as simple as adapting the width of the straps, but sometimes you're going to have to go through a whole series of pattern-making stages (for example, modifying the position of the "bottom of the trousers" in relation to the position of the pelvis; even modifying the bust size bust clips, ....

Let me give you a simple example: if you choose a traditional one-piece swimming costume with no bust darts, it will not be suitable for breasts of a D-cup and above. That's how it is. 

Before you start, take some time to choose a pattern. Make a prototype to validate the model and the size before making your final swimming costume and this is particularly valid when you are not in the "standard" of the pattern. I don't like to say "standard"... let's say that your measurements don't correspond exactly to a size in the pattern's measurement grid.

In the end, the swimming costume is not as simple as that?

It's a bit technical but when you get interested it's great to do. For me, it's not the field that interests me the most, so if I can give you just one piece of advice: go for it, look around, test it, try it and the result will be there... I always say tenacity and patience!

I think that some articles will complement this one.