Sourcing Sofas Without a Sit Test: Top 3 Determining Factors For Cushion Comfortability

Cushion Comfortability

How to determine cushion comfortability when my clients can’t sit-test was the question that plagued me for years. I did all the things: shopped retail, and then shopped retail with clients (eek!), took clients to local Designer Showrooms (less of an eek, but still), bought blindly (double eek!), wrote down every sofa I crossed paths with in High Point and gave it a 1-5 rating, consulted with a seasoned pro and even invested in an upholstery course. But with such a lucrative opportunity with wholesale vendors, I was unwilling to continue down this path. 

As an aside, I highly recommend the Upholstery Uncovered course. It was so worth it. Richelle goes in depth on EVERY. SINGLE. THING. UPHOLSTERY. I mean she leaves no stone unturned. The content of this article is not an all-inclusive look at upholstery.  

Before I jump to it, I want to give an incredible shout out to Cynthia Bleskachek of The Funky Little Chair whose Youtube video inspired this post, was an incredible wealth of knowledge as I wrote this, and who was kind enough to review this post for accuracy. 

Now If you know anything about me by now it’s that I like things clear and concise. I need a “this equals this” format for my brain to comprehend complex things. Knowing this about myself, I jumped off the deep end into all things cushion and upholstery to solve this problem for myself but also in hopes that it would help you too. This was no easy feat though as information was really limited. So I did extensive research, asked a lot of questions, 1:1 sessions with upholsters, testing and retesting to verify the information and then compiled all of my information into a single, (hopefully) easy-to-understand blog post. So let’s get to it…

A Quick Overview of Foam Numbers

Foam Numbers

A foam’s number comes in a 4-digit code. In this 4-digit code, the first two correspond to the Density and the second two correspond to the IFD rating. In the example above, the “18” refers to the Density. As foam is measured per cubic foot (PCF) this number would be 1.8. The second number, “35” is the foam’s IFD rating.₁ This four digit code is a factor in determining comfortability. Each number is independent of each other. One does not correspond to the other and both values are equally important. Let’s breakdown what each of those means. 

Step 1: Indentation Force Deflection (IFD)

The Indentation Force Deflection or IFD is measured by how much weight it takes to  compress a 12x12x12 cushion by 3” (or any size cushion compressed 25%). The result of this weight is the IFD rating. A machine is utilized to apply the force onto the foam’s surface, similar to the one depicted below. Lower IFD ratings offers a more plush or “sinking” effect when pressure is applied. Whereas a firmer cushion with a higher IFD rating will not “give” as much and remain stiffer under pressure₁.

The IFD is also referred to as Indentation Load Deflection or (ILD). 

Cushion Comfortability

As comfort is subjective, these numbers may vary by the source.
The numbers above are a general consensus based on my research but may be +/- 1-2 in either direction. 

In a nutshell: The amount of weight it takes to compress
Indication: Plushness/Firmness
Range: The typical range is between 10-60
Determination: The lower the number, the more plush the cushion is. The higher the number, the more firm it is. 

Ideal IFD’s:

  1. Dining Chair that is 1-2” thick: 45-70 IFD
    (preferable for a 2” thick cushion to be at 45 IFD)

  2. Standard Sofa Cushion that is 4-6” thick: Mid-30’s IFD

  3. Standard Back Cushion IFD of less than 20

IFD and Cushion Comfortability

Important Things to Note:

  • Seat backs should be more plush as they don’t take as much pressure as a seat cushion
  • The thickness of the cushion matters. The more material there is, the firmer it will feel. A 7” foam at 35 IFD will feel firm because there’s more foam to press down. When there is more foam to press down, you won’t go as far.
  • Knowing your clientele is important here.
    • A child is less likely to sink into foam than a heavy person.
    • Knowing the use is also imperative. If you’re lying down then weight distribution is wider, requiring less firmness. Sitting upright in a chair would require greater firmness. When sitting down or lying down, the foam will feel like a different firmness for each person₁.
  • A thinner cushion requires a higher IFD (a firmer cushion) to prevent “bottoming out”. Your client may want a comfortable dining chair but bear in mind that a low IFD on a dining chair really means when the cushion compresses they’ll be sitting right on the frame.

Step 2: Density

Foam density is a unit of measurement that demonstrates how much weight foam can support per cubic foot. Although you don’t need to do this yourself, the density of foam is measured by dividing the weight of the foam by its width x height x length. The denser (heavier) the foam is, the more tightly packed the membrane is, meaning more product is present per cubic foot, and therefore it has greater resilience and longevity. A higher density usually costs more because there is more “product” involved. And the life of the foam is expected to be longer

Foam Cushion Density

Density does not dictate comfort. Because of this, high density foams may be soft while low density foams can still be firm.

Density appears to have a small range between 1.0-3.0 but there are drastic differences between each value. In some cases the difference is between years or decades. Because longevity is key in our industry, I’m going to breakdown the different values and the how long you can expect it to last.

  • Fair Quality
    Density Rating: 0.8LB – 1.5LB
    High Traffic Lifespan: 6 months – 1 year
    Low Traffic Lifespan: Possibly up to 3 years
    Foam in this range is at the low end of density and can be considered fair quality; good for specialty uses and light applications. A density at the lower end means there is less physical foam mass in the material compared to higher densities, which leaves it prone to breaking down more quickly under use. ₄
Foam Density Ranges
  • Good-Quality
    Density Rating: 1.6LB – 2.4LB
    High Traffic Lifespan: 7-10 years
    Low Traffic Lifespan: Possibly up to 15 years
    In this range, you find materials that hold up to use better, are able to be used every day, and don’t cost an arm and a leg. Couch cushions and pillows at the higher end of the range are great products.₄
  • High-Quality
    Density Rating:
    2.5LB – 3.5LB
    High Traffic Lifespan: 15+ years
    Low Traffic Lifespan: Can exceed 20+ years
    Products with a density in this range offer the greatest quality available, earning their keep in the most demanding applications. You can get a much longer lifespan out of these products, as they hold up to the same amount of abuse for longer than lesser materials.₄

In a nutshell: How much a 12x12x12 foam weighs per cubic foot (PCF)
Indication: Longevity/Lifespan
Range: The typical range is 1.0-3.0 but can go up to 15.0. 
Determination: The lower the number, the lower the density., the shorter the lifespan. The higher the number, the higher the density, the longer the life span.
Important Things to Note

  • Heavy use, high density is best. Light to occasional use, medium density is best.
  • Typically, the higher density the foam is, the better the foam is at retaining heat

Step 3: High Resilience (HR) Foam

Guide to Cushion Comfortability

Not be confused as High Density, High Resilience foam is explained as:

“High Resilience is an excellent quality foam for furniture and mattresses and is available in most firmnesses. It is very buoyant and resilient, giving it high responsiveness. This means that it is fast to return to shape when pressure is applied and released, making it good for any application. This is ideal for those that want more bounce in their cushions. With an open-cell structure, High Resilience foam is very springy but still offers sturdy support. High Resilience foam lasts a very long time before it begins to get softer over the years.”

For these reasons, HR is the superior foam selection. Should you be sourcing a cushion and see an HR option, get it. It is worth the extra cost (and there is an extra cost). 

Indication: How the cushion recovers its shape after use
Density Range: 2.5-2.8
Ideal Use: Seats, sofas, and mattresses, and for heavy use furniture.

Real World Application

Now that you understand what each of these ratings are and how they determine longevity and comfortability, the second half of this is the translation into the real world. I experimented with several of my existing upholstery vendors and potential new ones to understand this process further. While many companies were able to identify either the IFD or Density, it was very rare to receive both. I was met with a myriad of responses such as:

  • “This is 2.5 Density, HR foam”
  • “This is a Marshall Spring with a down jacket”
  • “This is a medium/firm sit.”
  • “We label our options as Standard, Spring Down, Ultra Plush” 

all the way to…

  • “I’m 5’11”. This is a deep seat and my feet are firmly planted. The back rests at the center of my back…”

Unfortunately, there is no industry standard. Each vendor is its own protocol for identification. The best thing to do is narrow down your vendor list and spend quite a bit of time with your rep asking questions, feeling the product, and using a combination of methods to dictate your own findings.

This wasn’t the “this equals this” scenario I had hoped for so I dug further with Cynthia to find that magic recipe, as she explains. Continue reading here: Why Sourcing Upholstery is Like Baking and How to Deliver that Amazing Product.

₁ Foam How ₂ Red Fox Furnishings ₃The Funky Little Chair ₄ Foam Factory

Have additional questions or need me to clarify something? Leave a comment below and I’ll respond! 


Leave a Reply

  • Hi, I'm Kim!

  • I’m an Interior Designer, HGTV’s Designer of the Year – People Choices and your Interior Design Business Advisor. Through my systems and processes, I scaled my business to 6-figures and now I’m helping you do the same. 

  • Roadmap to Wholesale Design Course

  • Double Your Profits With The Same Number Of Clients By Changing Only One Small Detail In Your Interior Design Business

  • An Interior Designer’s comprehensive guide to implementing wholesale into your design business so that you can double your profits without taking on more clients. This course removes the overwhelm by giving you a simple, actionable, step-by-step roadmap to wholesale design. Click the button to learn more and enroll in the course!

  • Blog Categories

  • Client Experience

  • Mindset

  • Finances

  • Psychology of Selling

  • Let's Connect!

  • 🚨 Roadmap to Wholesale Design Course | NOW OPEN! 

    A 9-Step Approach to Implementing Wholesale and Maximizing Profit in Your Interior Design Business