March 20 2023
We'd all love to live in a world where all of our swimsuits fit perfectly, no matter the fluctuations in our weight or shape! But the reality is, sometimes your new bathing suit might not fit just right. Maybe it's not true to size, or maybe you still want to rock your favorite maternity suit postpartum. This is when it's really handy to know how to shrink a bathing suit!
Learning how to shrink a bathing suit is easy, and you may be surprised to find that most bathing suits can be safely shrunk with the proper method. In this article, we’ll look at how to shrink bathing suit bottoms and tops without damaging them. We’ll also learn the difference between the most common types of bathing suit material: nylon, spandex, and polyester.
Do Different Materials Require Different Shrinking Methods?
Before we talk about how to shrink a bathing suit, it’s important to understand what your suit is made of. Some methods for shrinking are slightly different, depending on the material. Some are hand wash methods and others you can do in the washing machine. Some materials are easier to shrink than others. It may require two or three attempts to get the results you desire.
Nylon is a synthetic, silk-like material made from petroleum. It is frequently used in athletic and swimwear because it is stretchy, quick-drying, and mildew-resistant. Nylon might be blended with other types of material (cotton blends are particularly popular), so read the label carefully to make sure you know exactly what materials are in your suit.
How to shrink a nylon bathing suit:
- fill a sink or basin with cold water and add ¼ cup of table salt
- submerge the suit and let it soak for 15 minutes
- remove the suit and gently squeeze out excess water
- place in the dryer on the lowest setting. Check it frequently to make sure it isn’t over-shrinking
- when it reaches the desired size, remove it and air-dry
Spandex (also called Lycra) is a synthetic material known for its incredible stretchiness and elasticity. It is a popular material for sportswear and bathing suits because it is strong, durable, and can be worn very close to the skin.
You can shrink a spandex or lycra bathing suit using the same method as for a nylon suit (outlined above.)
Polyester can be either natural or synthetic, but it is primarily synthetic polyester that is used to make bathing suits. Polyester is often blended with cotton to create a more pleasing look and texture. It is naturally resistant to shrinking, so it can be more difficult to shrink a polyester suit than a nylon or spandex one.
How to shrink a polyester bathing suit:
- fill a sink or basin with warm water and add ½ cup of white vinegar and some mild detergent
- vinegar is a natural fabric softener and will loosen the fibers of the suit to make shrinking easier
- submerge the suit and let it soak for 30 minutes
- remove it and gently squeeze out excess cold water
- place in the dryer on the lowest setting
- when it reaches the desired size, remove it and air-dry
Other Methods to Shrink Your Bathing Suit
The methods above are specific for each type of bathing suit material, but if you’re looking for a less-tailored or more generic approach, try one of the following methods.
The easiest and most common method for learning how to shrink a bathing suit is to use boiling water or very hot water. Simply boil a pot of water, submerge the suit in it (use tongs so you don’t burn your fingers!), and let the suit soak for about fifteen minutes.
Carefully remove the suit, gently squeeze out excess water, and place it in the dryer on the lowest setting, or line dry.
This method can be combined with the salt/vinegar methods described above, depending on the material of your suit.
The dryer can be used in combination with any other method to increase the amount of swimsuit shrinkage you achieve. We all know by now that putting some clothes in the dryer makes them shrink—bathing suits are no different! Just be careful to always use the lowest setting to avoid over-shrinking or damaging the suit.
How to shrink a bathing suit using the dryer:
- wash the suit in cool water and mild detergent
- submerge the suit in boiling water and let it soak for fifteen minutes
- remove, rinse with fresh water, and gently squeeze out the excess
- place it in the dryer
- for minimal shrinking, use a low setting. For maximum shrinking, use the highest setting
- check on the suit often to make sure it isn’t shrinking too much
- remove the suit when it reaches the desired size, and allow it to cool/air-dry
This is an advanced technique, only to be used by those who are comfortable with an iron! Be careful, especially with materials like nylon and polyester, because an iron at the wrong temperature can melt the fabric.
If you do choose to iron your swimsuit, use the following method:
- wash the suit in cool water, using mild laundry detergent (if you don’t, you’ll essentially be ‘baking in’ dirt and sweat residue in the fabric!)
- gently squeeze out water until the suit is damp
- place the damp suit on an ironing board and cover it with a cotton cloth (a pillowcase works well)
- never put an iron directly onto a damp bathing suit!
- set the iron to low heat or medium heat (never high)
- iron both sides of the suit using firm, slow movements
- keep ironing until all of the water has evaporated from the suit (it may take 10 minutes or more)
- air dry the suit (don’t put it in the dryer as it may over-shrink!)
In general, heat is the name of the game when it comes to bathing suit shrinking. High temperatures will shrink the fibers of the fabric, so if you don’t have access to a dryer or iron, get creative! You could put the swimsuit on a radiator, leave it in a hot car, use a hair dryer, or even just leave the suit in the sun (we don’t recommend the sun method unless you’ve exhausted all other options, as sunlight can damage the fabric of your suit.)
- If you are using a dryer to shrink your swimsuit, start with a low setting and check the suit often. High heat will shrink the suit more and faster, but you may end up going too far and end up over-shrinking the suit.
- Don’t over-soak the suit in salt or vinegar—both of these substances break down the fibers of the suit fabric. Exposing the suit for too long may damage the material. When you remove the suit from boiling water or a slat/vinegar soak, always rinse it, and avoid wringing out the suit—this will also stretch the fibers and damage the material.
- Don’t leave the suit in direct sunlight to dry. UV rays can damage synthetic fibers.
- Take it slow. You may not get the results you want right away, but don’t be tempted to go full blast with the dryer or crank up the heat on your iron! Instead, make two or three attempts with gentle heat to avoid burning, over-shrinking, or damaging your suit.
Summing It Up
Learning how to shrink a one-piece bathing suit, bikini bottoms, or bikini top is easy once you understand the core concepts: apply heat, use fabric-softening substances, and (most importantly) be gentle! If you don’t get the results you want right away, try another method until you get that perfect fit.
Once you learn how to shrink a swimsuit, your suit will be snug as a bug in no time!