Foam Series: Comparing Types of Cushion Foam

Item # X-HT-300053

With foam being the very core of every cushion project, it’s important to choose the right one for your application. Different types of foam have been engineered to float, drain water, prevent mold and mildew, and withstand daily wear. You want to choose foam with attributes that are compatible with the way you plan to use it. In this post, we’re going to take a look at all seven types of foam available at Sailrite® and discuss the basic properties and recommended applications for each.

For a visual aid to accompany this post, our Cushion Foam Buying Guide PDF breaks down the information here at a glance and can be helpful in comparing the properties of different foams.

7 Types of Cushion Foam

Compressed Polyester

Compressed Polyester foam

This is not actually foam, but rather densified polyester batting that creates an effective foam alternative. Compressed polyester will not disintegrate or yellow like traditional foam, but it will compress over time. An example of this is Fairfield Poly-Fil Nu-Foam, which is mildew resistant and nonallergenic. Nu-Foam is washable and will easily air-dry after getting wet. This foam alternative is an inexpensive option and is best used for occasional seating like patio cushions, light use upholstery and playpens.

Polyester Fiberfill

Polyester Fiberfill cushion and pillow stuffing

Like Compressed Polyester, Polyester Fiberfill is not truly foam, but rather blown polyester fibers. An affordable option, it is a common stuffing for pillows and deep seating back cushions. Generally, Polyester Fiberfill is stuffed inside a pre-sewn cover of Spun Bonded Pillow Protector Fabric, which is then inserted into the cushion or pillow fabric to give support and shape. Fiberfill is nonallergenic and resistant to mildew. It is machine washable, but the fiber can bunch up in laundering. Use your hand to smooth it back out.

Medium Density Polyurethane Antimicrobial Foam

Antimicrobial Polyurethane Foam in Blue (also available in white)

Medium Density Polyurethane Antimicrobial Foam is a traditional foam option with medium firmness that is suitable for seating and mattress applications. Polyurethane foam soaks up water when it gets wet, but the antimicrobial (sometimes called “biocide”) treatment on the foam helps to prevent the growth of mold and mildew as the foam dries out. Antimicrobial foam should be used where it is unlikely to get wet or it should be wrapped in a waterproofing layer, like Cushion Wrap Silk Film, before being inserted in the cushion cover.

Medium Density foam is great for boat seats, patio cushions and occasional indoor seating. In fact, OEM boat manufacturers commonly choose antimicrobial polyurethane foam for boat seating.

High Density Polyurethane Foam

High Density Polyurethane Foam for high-traffic cushions

This polyurethane foam is the same basic product as the Medium Density Polyurethane Antimicrobial Foam, but with a higher density. The higher density makes this foam more resilient, and therefore more suitable for everyday, high-traffic uses. High Density Polyurethane Foam is available in medium, firm and extra-firm firmness levels and typically lasts up to 12 years. Some high density foams are antimicrobial as well. This foam is best for upholstery seating, high-use interior applications, such as sofa cushions, and for interior settee and berth cushions in dry boats.

Dry Fast Open Cell Foam

Dry Fast Open Cell, water draining Foam

An open cell foam has open pores that allow water and air to flow through easily. Open cell foams make a comfortable and cool seating cushion or mattress. Dry Fast is a high-quality open cell foam. Dry Fast Foam is formulated with an antimicrobial agent to prevent mold and mildew. When paired with an outdoor cushion fabric or Phifertex Mesh, open cell foam creates a virtually maintenance free cushion in sun, rain and snow. These traits also make this foam great for boat cockpit cushions.

Dry Fast is a popular, user-friendly open cell foam. Due to its popularity, there are knockoff versions on the market. To see if your foam is high-quality Dry Fast Foam, pour a cup of water on it. The water should run straight through the foam and drain out the bottom. If the water runs off the sides of the foam, this is an imitation Dry Fast Foam.

Closed Cell Foam

Closed cell flotation foam

Closed Cell Foam resists moisture absorption, making it buoyant. This foam is made from PVN and is three times firmer than polyurethane foam. It is also a more expensive option. Closed Cell Foam is great for flotation applications like floating cockpit cushions and life vests. It is also a good choice for commercial boat seating, or other seating that will be used as a step for getting on and off the vessel. This foam has no water absorption, so you can safely cover it with any type of fabric. Thin sheets of Closed Cell Foam are often glued to the bottom of other foam, adding additional support for the cushion, like a box spring to a mattress. When used with Dry Fast Foam, you need to cut holes in the Closed Cell Foam for drainage.

As you can see, there are a lot of foam options out there, so it should be no problem to find one that is just right for your next project.

Fabric Backed Sew Foam

Fabric Backed Sew Foam

Fabric Backed Sew Foam is a thin sheet of polyurethane foam that is perfect for upholstery applications. Also known as polyurethane foam with fabric backing, scrim foam or sew foam, it features a spun-bonded polyester backing that holds adhesives very well, making the foam easy to glue in place. The backing holds stitches so you can sew through the foam to create pleats or channeling in your upholstery work, such as with motorcycle, pontoon and powerboat seats, golf cart backrests and coaming pads.

It is not a substitute for actual cushion foam. It is a way to pad and soften hard edges and also to add texture to seating by creating sewn quilted patterns in the covering fabric. Fabric Backed Sew Foam is also used in headliner applications. Sailrite offers Fabric Backed Sew Foam in 1/2-inch and 1/4-inch thicknesses. Both sizes are used for all the applications listed above, but 1/4-inch sew foam is ideal for sewing quilted bags and purses as the foam is thin enough to be flexible and easily shaped.

Did you run into terms in this post you were unsure of? Our “5 Important Foam Terms to Know” (#300052XHT) post can help!