Baby Sleep Sack: Is Cotton the Best Material for Babies?

Baby Sleep Sack: Is Cotton the Best Material for Babies? Hero Image

The first material most parents think of looking for when buying children’s clothes is cotton. This makes complete sense as it ticks many different boxes from affordability to suitability to children’s skin.

However, not all cotton is made equal and simply going into a shop or browsing online for just “cotton” doesn’t help you narrow down your search

In this blog, we offer parents some pointers on what type of materials to look for when buying pajamas, sleep suits and baby sleep sacks.

what should baby wear to sleep - materials infographic


Why Cotton for Baby Sleep Sacks?

Cotton has many great attributes. It's strong, durable and less likely to rip or tear than many other materials. It also washes and dries easily and can be washed as many times as needed.

When we're thinking about babies specifically, the fact that cotton is naturally soft is one of its best attributes, making it suitable to even the youngest infants whose skin can be incredibly sensitive to materials

It offers breathability and can help children stay cool in summer too (allowing heat to escape the body when babies are young and have a harder time regulating their body temperatures), while offering a good amount of insulation if cotton layers are doubled up. 

Cotton offers breathability and can help children stay cool in summer too (allowing heat to escape the body).

Try Our Zipadee-Zip Baby Sleep Sacks (Cotton & Synthetic Blend)


Photo of baby in a baby sleep sack cotton Zipadee-Zip


At Sleeping Baby, we have a number of 100% organic cotton baby clothing options for parents who prefer to use completely natural materials. Due to the nature of 100% cotton, shrinkage can sometimes occur so we recommend washing your Zipadee-Zip in cold water and only hang drying.

For those looking for some added stretch and flexibility, we also offer cotton blend options for our Zipadee-Zips (55% cotton, 45% modacrylic), which are available in three sizes (M, L, XL). These are great for parents who want a fabric that’s a practical “all-rounder” that can withstand any kind of baby kicking or growing as well as frequent washing. 

All our products have been tested to make sure they’re suitable for infants with extra sensitive skin. You can check out what other parents think in the reviews of any of our product pages!

Suitable Material Options for Baby Sleep Sacks

Mother sitting next to folded pile of folded baby sleep sacks made from cotton material

In 2019/2020, the total global production of cotton amounted to some
122 million bales (that is a lot!). So one of the first things to remember is that it's the most often used natural fiber worldwide and there are different types of cotton grown around the world, which are in circulation in a variety of products. 

Cotton is a kind of general term that can encompass many different types of fabrics that fall within this category.

Also, many clothing options for kids (whether it's rompers or baby sleep sacks) are blended with other materials, such as synthetic fabrics. This isn’t always a bad thing, but it’s worth thinking about when you’re trying to build a versatile and hardwearing wardrobe for your little one. 

Therefore, for the purpose of choosing the best material for your child, the following is a list of common types parents look to when buying a swaddle, sleep sack or infant pajamas.

Linen (Top Choice for Summer)

Linen is generally a top choice for summer and avoided in winter months when your child needs more protection from drafts and heat escape. It’s incredible because it is so thin and lightweight due its loosely woven nature. We find that many parents also choose linen because of its aesthetic appeal, offering a kind of raw sophistication that other fabrics don’t.

The downsides are that linen requires more maintenance as it gets crinkled really easily, and if you don’t wash it at the right heat (gentle wash) and with the right products (mild detergent and no bleach) you can ruin the product. It's also usually a tad more expensive than more simply cotton options so it’s not exactly the go-to option for the day-to-day baby sleep sack. 

For tips on how to dress your baby in warmer weather, take a look at our blog: What Should My Baby Wear to Sleep in Summer? Simple Tips for a Great Night’s Sleep!


Rayon is becoming incredibly popular today. It is a man-made fabric blended from cotton, wood pulp, and other natural or synthetic fibers. Some would compare it to silk because of its flowy and smooth texture, which is also great for summer.

Again, this option is a little harder to maintain than simple cotton fabrics and sometimes requires hand washing or even dry cleaning to keep in good condition. Therefore, it might be a good option for some fun summer BBQ outfits, but maybe not for more day-to-day situations.

Lawn Cotton

Young boy examining different clothing products in shop including cotton baby sleep sacks


Lawn cotton is designed using high thread count yarns and results in a silky and untextured feel. It is a lightweight fabric and it can be slightly transparent with a slightly crisp feel to it. At the same time, it’s usually very soft to the touch and can be used for many different types of clothing for children. It’s also great in winter

Muslin (Top Choice for Sensitive Skin)

Muslin is an extremely fine and loosely-woven cotton fabric available in many different weights, sizes and finishes. These can range from very thin to quite dense or coarse. As such, it can be worth checking with your hands how soft and light this material is before buying it

The best muslin will be incredibly soft and perfect for baby clothing, including swaddles, bodysuits and baby sleep sacks of various different types and varieties. 


Most adults will own a good amount of broadcloth in their wardrobes. The fabric, which is lightweight and smooth, is often found in shirts either as pure cotton or a blend with synthetics. It’s a suitable option for children and you’ll find it in many major retailers. 

Fleece (Top Choice for Winter)

We love fleece because it keeps kids warm and cosy during the winter months without being stuffy, scratchy or irritating. Unlike certain types of wool, fleece is easy to maintain and can be washed as much as you need while also offering quick drying times. 

Organisations such as the American Academy of Pediatrics advise that all parents keep soft objects, loose bedding, or any objects that could increase the risk of entrapment, suffocation, or strangulation out of the baby's sleep area. As such, upgrading to a warmer material like fleece is much better (and safer) during colder months than adding loose layers like sheets and blankets.

Looking for Baby Jammies? Here’s Our Advice!


Best Material for Baby Sleep Sacks? Cotton and Synthetic Blends!

Mother opening draw full of baby sleep sacks made from cotton and other materials


Some prefer to avoid synthetic clothing options altogether when buying baby clothing like rompers and baby sleep sacks, in favour of 100% natural products, however, we believe there is often an unnecessary stigma attached to this group of materials. 

We find that certain blends can emphasise the already great qualities of cotton and improve certain things like stretch capacity, drying times, and water resistance. 

Our lightweight collection at Sleeping Baby, for example, draws on the breathable and flexible qualities of polyester to offer children a great option for warm weather, while still offering the style and comfort benefits of pure cotton. 

Check Out Some of Our Reviews from Happy Parents!

Alternatives to Cotton

For those who would rather not buy cotton or synthetics, there are also a few alternatives on the market that offer good properties for children’s clothing. The availability of these can vary, however, they are worth looking out for if you want to consider other options. 

  • Hemp
  • Bamboo
  • Ramie
  • Flax

Materials to Avoid for Baby Sleep Clothing

A basket of wool yarn with scratchy and irritating texture


Synthetic Blends (Sometimes)

For children who have really sensitive skin or eczema, materials that are synthetic, can increase itchiness and perspiration.


Certain types of wool can be far too rough and scratchy on your little one’s delicate skin.


Fibers in fur can easily be pulled out and ingested, which poses a choking hazard. In addition, some children may have an undiagnosed allergy to certain types of fur.


What About Merino Wool?

Parents often worry that wool will make their babies hot and clammy. This is true in cases where the type of wool is cheap and scratchy. However, merino wool children’s clothing can be really soft and smooth to the touch, as well as help babies stay at a comfortable temperature due to its thermo-regulating abilities

Tips for Handling Baby Clothes

Whatever fabric you choose for your baby sleep sack, there are some simple tips that can help you make the most of it and support baby comfort and health. 

  • Pre-wash your sleep sacks and other baby clothes before you let your baby wear them for the first time. As baby skin is so sensitive, you must ensure you get rid of any chemicals or irritants that could cause a bad reaction.
  • <strong>is soft and non-irritating. For instance, buttons, clips, strings or other accessories could actually scratch or harm your baby and should be removed.
  • Create a separate day-to-day and special occasions wardrobe. The former should be hard-wearing, easy to wash and generally robust, while the latter can be more especially pleasing and fancy. By distinguishing these groups, you can help to protect the clothes they might be a little more visitor-friendly. 

Pre-wash your sleep sacks and other baby clothes before you let your baby wear them for the first time.

Final Tips for Choosing Baby Sleep Sack Fabrics


Mother organising infant wardrobe and baby sleep sacks made from cotton


Most clothes designed for babies will naturally be comfortable and cozy. However, it’s always good to do a quality check for the exact materials that your garment is made from and check for any zippers, snap buttons and elastics that could cause your child discomfort.

Cotton is great, but there isn’t just one material (or type of cotton) that will work in all environments and temperatures. Often you will have to dress for the moment and add (or remove) layers so your baby maintains a good overall temperature. 

As you would for yourself, common sense is the ebay way to approach baby clothing materials. Heavy materials are better suited to winter just as lighter materials are great for summer. And a good general rule is to dress your little one in slightly warmer clothing than you would be comfortable wearing yourself.