Let’s talk carrier padding.

This might not be the most exciting topic, but foam really can make the difference between a comfortable, professional carrier and one that you’ll chop up for parts later.

Each Sew Toot carrier pattern calls for a certain type and thickness of padding for optimal comfort and in certain cases, function.
It’s best to stick to the recommendations as closely as possible, but at the bottom of this post I’ll talk a few areas where it’s safe to deviate.

Open Cell Foam

Open cell foam is a soft, “cushion” type of foam– think of an office chair, couch cushion, or memory foam.  If it looks like foam and it’s squishy, it’s likely open cell foam.
To get technical about why it is called “open cell” foam — the cells inside the foam are “open” which allows air to penetrate the foam. This is the reason the foam can be compressed– you’re squeezing the air out of it.

So what are the benefits to using open cell foam? 
It adds cushion and cushion = comfort.

Open cell foam comes in different thicknesses (1/2″, 1″, 1 1/2″, 2″, etc.).  It also comes in varying densities.  One really important thing to know about open cell foam (other than that it’s the “cushion” type of foam) is that the amount of support it offers is measured in something called “ILD” or indentation load deflection.

So think of a piece of foam and placing a heavy weight on top of it.  A piece of open cell foam with a lower ILD would be pressed flat by the weight.  As the ILD increases, it means that the foam withstands compression under a higher amount of weight placed over the surface.  For those of us making carriers, this figure is completely relevant because we’re carrying weight over our bodies and using foam to help to distribute weight and eliminate pressure points.

A good baseline ILD is 36.
I don’t recommend using a foam with a lower ILD than 36 for baby carriers, especially for the straps because it will compress too easily under the weight.  I’d say the ideal range is between 50-60 ILD.

How do you find the ILD rating?  

Foam manufacturers and retailers can provide you with this information.  You can email internet retailers if the information is not readily available.
The [green] open cell foam sold in Joann Fabrics across the U.S. that many of you are using for carriers has an ILD rating of 36.

The open cell foam offered in the carrier supply kits on the website are at minimum 50 ILD [with the exception of the doll carriers].

Other open cell foam considerations

Not all open cell foam is water friendly. For use in water applications, there are certain types of foam that are quick dry available through plenty of sources on the internet.
ILD and foam thickness are less critical in open cell waistband applications.

Closed Cell Foam

Closed cell foam is more of a “solid” type of foam.  A great example is a yoga mat– many of us are familiar with the way they feel.
Closed cell foam is aptly named because the air pockets are closed off. This explains why there is not any air to compress out of the foam.
When you squeeze it, it won’t compress much at all.
There are plenty of varieties of closed cell foam — Ensolite, Neoprene, cross-linked polyethelyne, etc.
In general these are more structured than open cell foam, thickness plays a big role here.  If you take a thin sheet (1/8″) of neoprene, it’s not going to feel very structured or rigid.

Neoprene in a 3/8″ thickness will definitely lend some structure to a waistband though.

Closed cell foams that are 3/8″ and greater in thickness are best suited for waistbands in soft structured carriers.

Closed Cell Foam Applications

Closed cell foam is great for waistbands and anywhere you need to add a bit of structure.
It’s water resistant, so it’s perfect for water friendly carriers too.

Can closed cell foam be used for straps?
I’d say yes, to an extent.  Closed cell foam works great for straps like The Voyager [by Sea] where the carrier needs to be water friendly.
For everyday wearing and especially extended wearing, I’d recommend using open cell foam or pairing the closed cell foam with a layer of open cell foam.

Quilt Batting and Fleece

Quilt batting and fleece fabric can be used as padding in baby carriers as an inexpensive alternative to foam.

Many people choose to go this route because the two are readily available and can be quilted with unique designs.

These are typically cut to the shape of the pattern piece and stacked in several layers (usually between 3-6 depending on desired thickness).

For waistband applications, I prefer to use 6 layers of quilt batting and then quilt horizontal lines across the waistband for a bit more structure (though of course you can quilt any design you’d like!)

I generally prefer to leave quilt batting and fleece for waistbands and avoid using it in shoulder straps except for certain carrier styles where light padding is preferable (bei dai).