Foam Series: 5 Important Foam Terms to Know

SKU: X-HT-300052



Choosing the best foam for your application can make a world of difference in the cushion’s comfort and performance. Which type of foam will make the best cockpit cushion, which is better for sleeping, and which type of foam is perfect for patios? To look at those issues and address your most burning foam questions, we’ve put together a helpful series of articles, videos and infographics.

To make the best foam selection, it’s helpful to understand the different specifications and terminology you’ll run into when shopping for foam. With a base understanding of these terms, you’ll be a step ahead in knowing what to look for when buying foam for any application.

Expressed as weight in pounds per cubic foot, density is the most important property to consider when choosing foam. Density is a measurement of how little air is in the foam. Generally speaking, the higher the density, the better grade of foam. However, for certain projects a very high density can be considered excessive.

For example, for boat cushions, the industry standard is only 1.2 pounds per cubic foot for seat backs and 1.5-1.8 pounds per cubic foot for seats. At Sailrite®, that's our CushionRite® Standard Antimicrobial Foam. These densities are considered fine for occasional use such as on seasonal boats and patios. Indoor applications that see daily, year-round use or applications for liveaboard cruisers would require a much higher density for longevity; in these cases, look for a density of 2.5 pounds or better. Search for CushionRite® Premium Foam for a long-lasting, high density polyurethane foam.

This is a measurement of foam’s firmness and is found through testing. During the test, a 50-square-inch circular plate is pressed down onto the foam to a given deflection and then the force is read on a scale. The IFD represents how many pounds it takes to compress the plate 25% of the way into the foam. In general, the range of Sailrite products’ firmness can be broken down into the following ranges: less than 24 pounds is extra soft, 25-39 pounds is soft, 40-59 pounds is medium, 60-75 pounds is firm, and 76 pounds or higher is extra firm.

Antimicrobial means the foam contains an additive that reduces fungus growth. This type of treatment is recommended for outdoor foams that don’t easily drain water like polyurethane foams. At Sailrite, we offer a variety of foam types with this very important additive. Just look for a foam with “Antimicrobial” in the title.

You’ll see this term used in reference to our CushionRite® Dry Fast Antimicrobial Foam. Reticulated, in the foam world, is used in reference to open cell foam. Foams described as reticulated have had their cell walls blown out, which leaves an open cell structure through which air and water can easily flow. The trademarks of these foams are breathability and water drainage.

On the Sailrite website, you’ll see that you have the option to narrow down your foam choices between “occasional” and “frequent” use. These options are really important in order to select a foam with the best longevity for your application. For occasional use, think weekend boaters, patio seating and infrequently used upholstery (like in a formal living room). When it comes to frequent use, think of seating you use daily or nearly daily like your family room sofa or the settee cushions of a liveaboard boater.

To continue learning more about foam, head over to the next post in our foam series “Comparing Types of Cushion Foam” (#300053XHT).