Foam selection for upholstery: What you need to know

Crypton by C.F. Stinson

This week on YouTube, we’re creating the cushion inserts for Aunt Bea.


Cushions are tricky business. “Comfortable” is endlessly subjective, and the margin of error is alarmingly small, considering that foam and fabric are infuriatingly imprecise

I wouldn’t presume to answer all your cushion questions in one post (even if I COULD answer all your cushion questions) but I WOULD like to offer some basic product information to hopefully make your job a bit easier.

Let’s talk about foam.

There are so many ways to fill a cushion – springs, cotton, down . . . Personally, I’m a foam girl – it’s relatively easy to work with – versatile and cooperative. My local supplier, Fabric Supply Incorporated, offers a wide, quality selection, so I’m able to give my clients great options and information.


But. But, but, but.

If you’re going to work with foam, you need to make informed decisions.

I worked for several years at a local business called  A-1 Foam & Upholstery. They specialize in retail foam sales and cushion replacement. And boy oh boy, did I learn about FOAM!!!!!! Now that may not sound super exciting to you, but I can tell you that, as an upholsterer, it’s VERY exciting to look at a foam catalogue and know what the heck is going on. It’s exciting to be an informed resource for your clients. It’s exciting to speak about cushion options from years of first hand experience.

Many of our  customers  came to us by way of a disappointing experience at the fabric store. They’d purchased foam for their deflated cushions, or for a DIY project, and learned in a hurry that not all foams are created equal.

If you want to understand foam, and be an informed resource for your clients, you need to understand THE NUMBERS.


Labelling and verbiage will vary from supplier to supplier, and many try to simplify the information with subjective labels like, “medium soft” or”extra firm” but in order to compare foams, you need to ask for NUMBERS!

TWO numbers in particular:


Contrary to popular opinion, these are NOT the same thing.

FIRM is how hard a foam is. DENSE is how heavy a foam is.

Let me explain . . .

Firmness is expressed as an IFD (Indentation Force Deflection)

It’s basically a test of how many pounds it takes to compress any given foam a certain distance.

For example, an average 4-6″ seat cushion is going to have an IFD of around 30.


If you’re dealing with a low-profile seat (like a dining chair or church pew) you need something firmer, perhaps an IFD of 45-60. Otherwise, you’ll sit all the way down to the board.


For loose backs, you typically want  a lower IFD, something under 20. Seat cushions take all our weight, while backs receive only a fraction. An IFD of 30 that feels comfortable in a seat will feel extremely firm in a back.


How firm a foam feels also becomes relative when you look at how, and by whom, it’s being used. For example, a 40 pound child sitting next to a 200 pound man, shows that “perfect” IFD is relative. It’s good to consider who you’re upholstering for.

Likewise, consider how your sofa feels when you sit on it, versus when you lay down. Same weight, but spread over a much larger area, so the foam won’t compress as far. It FEELS firmer.

Shhhhhh cushion testing in progress . . . .

This makes it tricky to choose foam for things like campers, where the same foam may be used for seats AND backs, then convert into a bed.

Fun, right??

Let’s not overcomplicate the issue too much. The bottom line is, IFD tells you how firm a foam is in relation to other foams. Don’t rely on meaningless, generic terms. Get those numbers and start using them to be an informed resource for your customers.

NOW, let’s talk about density.

DENSITY is how heavy your foam is. It’s expressed as a weight per cubic foot.

DENSITY is your best indicator of longevity. It essentially tells you how much product the foam contains (versus air). A better foam has more product crammed into the same cubic foot.

Density for upholstery foam will range from about 1# to just over 3#.

THIS is the number you need to compare quality, and it is most closely associated with cost (in case nobody told you, good foam is pricey stuff)

As a rough guideline, a 1# foam can be expected to last about a year with regular, everyday use. (frankly, I think that estimate is optimistic)

A 3.1# foam (like we use for the seat cushion on Aunt Bea) is considered a 10-14 year foam, depending on who you ask.

You don’t need the densest foam for every application – lower density foams are frequently found in window seats and camper cushions, for example. There are times when it makes sense to spend less.

But for the sofa in your busy living room, a low density seat foam will disappoint in a hurry.


Shelf life on a foam will depend upon who’s sitting on it, how often and for how long. Cushions that can get flipped and swapped will naturally last longer than odd shaped cushions that never get rotated (like the asymmetrical chaise on a sectional sofa)

The same foam will last much longer in a guest bedroom than it will in your favorite chair.

If the only person who ever sits on it is your 90 lb grandma, a good cushion could last dang near forever. If, however, the high school football team hangs out at your house every day . . .

Do you see what I’m getting at?

When we talk about “how long will a foam last” there are loads of variables in the mix. . . But density is your best tool for determining the answer.

Now here’s where people often get tripped up:

A foam MAY be both firm and dense . . .  but then again, it may not.

Sometimes, a foam is very DENSE but not firm: Like a high-end bed topper, for example. It starts soft, and stays soft, for a long time, without flattening out.

My mattress has a 2″ topper. The density is 2.4# and the IFD is 18.

Heavy. Soft. Amazing.

Likewise, a foam may be FIRM but not particularly dense. There are places for a foam like this – we sometimes sold it for small, elderly dogs who needed steps or ramps to get on the bed. True story.

Unfortunately, thinking you bought a dense foam, when you really bought a firm foam, that’s a bummer.

Unknowing consumers, disappointed with cheap, cushions, often think that the answer is a firmer foam. But if their new foam has a low density, it ends up being a disappointingly quick fix.

Hopefully, using this information, your foam options seem a little less cryptic. The truth is, the best way to understand foam is to get your hands on it. My preferred wholesale supplier is Fabric Supply, Incorporated in Minneapolis. They were happy to provide  samples for the shop, which I frequently share with students and clients. If you want to use good foam, you need to understand it, so don’t be shy about asking your supplier questions. And if the foam supplier you’re using can’t provide detailed, specific information, FIND A NEW SUPPLIER. I don’t care if they offer, “super-duper-premium-deluxe” – NUMBERS NUMBERS NUMBERS!

While you’re talking to them, you can also learn about things like fire retardancy, high-resiliency, and specialty foams (Filter!!! Closed cell!!!!)

Really, foam is a surprisingly complex and interesting topic.

Shut up, I’m not a nerd, you’re a nerd.

Okay, that’s the longest I’ve ever written about foam, and I’m ready to stick toothpicks under my toenails.

So let’s shift gears and talk specifically about the cushions for Aunt Bea.

If you want a video walk through on creating two relatively simple cushion inserts, hop on over to YouTube.

As promised in our video notes, here are the links for what we used (nope, not affiliate links. Just stuff I  use that I think you’d like.)

(Please note that you must have an account with Fabric Supply in order to purchase from them)


Lastly, if you want a quick pick of foams that I use on the regular, here’s you go!

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That’s it for this week!!!! What should we write about next week? Frankly, I can’t think of anything as exciting as a 1500 word post about foam. But we’ll try . . . we’ll try. 

Happy upholstering, everyone! 

Cynthia 🙂

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