Whether a sofa, chair, sectional, or chaise, we all love the irresistible comfort of our coziest pieces of furniture. It’s where we unwind every evening and sneak in a midday nap whenever we get the chance. But how is upholstered furniture made, what makes a sofa comfortable, and what sets the highest quality pieces apart from the rest?We’re breaking down everything that goes into making upholstered furniture, from frame construction to support systems to the most comfortable sofa cushions ever. For more insights on upholstery construction, read our next post in this series: "Sofa Styles: The Design Details That Elevate Each Silhouette."
The diagram above shows the common elements of any upholstered piece. Most are self-explanatory, but we’ll walk you through a few of these terms. The frame is made of wood and forms the interior shape of the furniture. Think of the frame as the skeleton; it’s what provides strength and structure for all that goes on top of it. The decking is the platform that supports the seat cushion, providing comfort and durability. The apron is the layer of separation between the base and the seat cushion. The arm gives upholstered furniture shape and personality. In the silhouette above, our Amelie slipcovered chair, the simple roll arms sweep subtly outward, giving the chair an elegant and inviting profile.
What’s Inside Upholstered Furniture
The construction methods, pitch (the angle of the seat back in relation to the seat), and fill materials determine the level of durability and comfort of any given seat. The interior of any upholstered furniture will often feature a wood frame, at least one layer of padding (typically polyester fiber, polyurethane foam, and/or batting), and a suspension system. We’ll dive into this more below.
Shop Custom Sofas
Madeline Velvet Sofa
Amelie Slipcovered Sofa
Henri Slipcovered Sofa
Adelle Slipcovered Sofa
Hartwell Sofa
Willett Velvet Sofa
Frame Construction & Joinery
The frames in our collections use a combination of hardwoods and engineered hardwoods. Most of the hardwoods we use are FSC® Certified, formaldehyde free, and sourced from forests in the U.S. The wood typically undergoes a kiln-drying process that helps prevent twisting, warping, or cracking over time.
Mortise-and-Tenon Joint
Double-Dowel Joint
Corner Blocks
Joinery describes the methods used to connect pieces of wood together. Our custom upholstered furniture utilizes a mix of mortise-and-tenon and double-dowel joints. The joints are reinforced with corner blocks to provide solid and long-lasting frames—no wobbling, ever.
Suspension Systems
The suspension system sits directly below the cushions and supports any weight placed on the seat. Steel springs or synthetic webbing form this layer of support, which is a factor in determining how plush or firm the sit will feel.
8-Way Hand-Tied Suspension
Considered the gold standard in suspension methods, eight-way hand-tied is the most labor intensive and costly construction, all done by hand by a skilled craftsman. It is used for its high quality and longevity, creating heirloom-quality pieces built to last decades. Eight-way hand-tied suspension requires the use of premium materials and is unmatched in terms of durability and comfort. Furniture with this suspension system will feel exceptionally supportive and perfectly solid even after years of use. You’ll find this method used in many of our pieces, including our Amelie and Henri collections.Individual coil springs are hand-knotted with twine at eight points on each spring and attached across the seat’s frame, allowing the springs to move independently while remaining balanced. This web of twine keeps the springs from shifting, providing years of unwavering support. The use of twine instead of metal also ensures that the suspension won’t start to squeak with use.
Sinuous Springs Suspension
Sinuous springs suspension is a more common and less labor-intensive method than eight-way hand-tied springs. In this suspension system, tight S springs are attached across the frame and placed four to five inches apart to ensure consistent comfort. These springs are made from heavy-gauge steel and designed to withstand years of use.
Webbing Suspension
Webbing suspension is most common on smaller furniture like ottomans and multi-piece modular sectionals. In this suspension method, polypropylene bands are crisscrossed and attached to the frame. This is a more affordable suspension method that still offers plenty of comfort and durability (and no squeaking, ever).
Shop Custom Sectionals
Hartwell Corner Sectional
Donato Chaise Sectional
McKinley Corner Sectional
Irene Corner Sectional
Weybridge U-Chaise Sectional
Adelle Bumper Sectional
Cushions
Most cushions in our custom upholstery assortment start with a high-resiliency foam core that’s supportive, durable, and easily regains its shape. Surrounding the core is a jacket containing synthetic fibers and/or natural down and feathers. This jacket is typically channeled to disperse the fill materials evenly. These are a few of our most popular cushion types:
Ultra Luxe Down Cushion
A premium soy-based, high-resiliency foam core is wrapped in an envelope of 90% feather and 10% duck down, then encased in a downproof ticking and sewn into channels to maintain an even sit. Back cushions are filled with a mixture of 90% feather and 10% duck down.These down-filled sofa cushions offer the sink-in comfort we love. It’s the seat you’ll look forward to returning to day in and day out—trust us.
Plush Down Blend Cushion
A high-resiliency foam core is inserted into a channel-quilted casing filled with a blend of 50% polyester fiber, 5% down, and 45% feather, then finished with a downproof ticking. Back cushions are filled with a mixture of 50% polyester fiber, 5% down, and 45% feather.This cushion fill provides our classic plush yet supportive sit. It’s cozy, very comfortable, and requires less fluffing maintenance than cushions with only down and feather.
Soft Down Alternative Cushion
A high-resiliency foam core is wrapped in an envelope filled with hypoallergenic polyester fiber that offers all the benefits and comfort of down, without the need for fluffing. Back cushions are filled with polyester fiber. These low-maintenance sofa cushions provide a wonderfully soft and supportive sit. They have all the plush comfort and none of the upkeep—simply settle in and enjoy.
Firm Down Alternative Cushion
Our most firm cushions are filled with layers of foam. These cushions start with a high-resiliency foam core which is then surrounded by a layer of medium-density foam and/or a super soft foam layer.This cushion fill offers a sit that's firm yet comfortable and very supportive. It provides a tailored look that's never sloppy and needs zero maintenance to continue looking fresh. Our super comfortable sectional sofa, Donato (click the image to shop!)
Kathy Kuo Studio
Need design help? Kathy Kuo Studio is a full-service design firm working with clients in the United States and abroad. From warm, timeless interiors to serene outdoor retreats, our talented team of accredited designers creates spaces that feel like home, designed around how you live and what you love.
The diagram above shows the common elements of any upholstered piece. Most are self-explanatory, but we’ll walk you through a few of these terms. The frame is made of wood and forms the interior shape of the furniture. Think of the frame as the skeleton; it’s what provides strength and structure for all that goes on top of it. The decking is the platform that supports the seat cushion, providing comfort and durability. The apron is the layer of separation between the base and the seat cushion. The arm gives upholstered furniture shape and personality. In the silhouette above, our Amelie slipcovered chair, the simple roll arms sweep subtly outward, giving the chair an elegant and inviting profile.
The construction methods, pitch (the angle of the seat back in relation to the seat), and fill materials determine the level of durability and comfort of any given seat. The interior of any upholstered furniture will often feature a wood frame, at least one layer of padding (typically polyester fiber, polyurethane foam, and/or batting), and a suspension system. We’ll dive into this more below.
Madeline Velvet Sofa
Amelie Slipcovered Sofa
Henri Slipcovered Sofa
Adelle Slipcovered Sofa
Hartwell Sofa
Willett Velvet Sofa
The frames in our collections use a combination of hardwoods and engineered hardwoods. Most of the hardwoods we use are FSC® Certified, formaldehyde free, and sourced from forests in the U.S. The wood typically undergoes a kiln-drying process that helps prevent twisting, warping, or cracking over time.
Joinery describes the methods used to connect pieces of wood together. Our custom upholstered furniture utilizes a mix of mortise-and-tenon and double-dowel joints. The joints are reinforced with corner blocks to provide solid and long-lasting frames—no wobbling, ever.
Considered the gold standard in suspension methods, eight-way hand-tied is the most labor intensive and costly construction, all done by hand by a skilled craftsman. It is used for its high quality and longevity, creating heirloom-quality pieces built to last decades. Eight-way hand-tied suspension requires the use of premium materials and is unmatched in terms of durability and comfort. Furniture with this suspension system will feel exceptionally supportive and perfectly solid even after years of use. You’ll find this method used in many of our pieces, including our Amelie and Henri collections.
Individual coil springs are hand-knotted with twine at eight points on each spring and attached across the seat’s frame, allowing the springs to move independently while remaining balanced. This web of twine keeps the springs from shifting, providing years of unwavering support. The use of twine instead of metal also ensures that the suspension won’t start to squeak with use.
Sinuous springs suspension is a more common and less labor-intensive method than eight-way hand-tied springs. In this suspension system, tight S springs are attached across the frame and placed four to five inches apart to ensure consistent comfort. These springs are made from heavy-gauge steel and designed to withstand years of use.
Webbing suspension is most common on smaller furniture like ottomans and multi-piece modular sectionals. In this suspension method, polypropylene bands are crisscrossed and attached to the frame. This is a more affordable suspension method that still offers plenty of comfort and durability (and no squeaking, ever).
Hartwell Corner Sectional
Donato Chaise Sectional
McKinley Corner Sectional
Irene Corner Sectional
Weybridge U-Chaise Sectional
Adelle Bumper Sectional
A premium soy-based, high-resiliency foam core is wrapped in an envelope of 90% feather and 10% duck down, then encased in a downproof ticking and sewn into channels to maintain an even sit. Back cushions are filled with a mixture of 90% feather and 10% duck down.
These down-filled sofa cushions offer the sink-in comfort we love. It’s the seat you’ll look forward to returning to day in and day out—trust us.
A high-resiliency foam core is inserted into a channel-quilted casing filled with a blend of 50% polyester fiber, 5% down, and 45% feather, then finished with a downproof ticking. Back cushions are filled with a mixture of 50% polyester fiber, 5% down, and 45% feather.
This cushion fill provides our classic plush yet supportive sit. It’s cozy, very comfortable, and requires less fluffing maintenance than cushions with only down and feather.
A high-resiliency foam core is wrapped in an envelope filled with hypoallergenic polyester fiber that offers all the benefits and comfort of down, without the need for fluffing. Back cushions are filled with polyester fiber.
These low-maintenance sofa cushions provide a wonderfully soft and supportive sit. They have all the plush comfort and none of the upkeep—simply settle in and enjoy.
Our most firm cushions are filled with layers of foam. These cushions start with a high-resiliency foam core which is then surrounded by a layer of medium-density foam and/or a super soft foam layer.
This cushion fill offers a sit that's firm yet comfortable and very supportive. It provides a tailored look that's never sloppy and needs zero maintenance to continue looking fresh.
Our super comfortable sectional sofa, Donato (click the image to shop!)
