Initial Load Deflection (ILD): A measure for the firmness level of foam used in upholstered furniture and mattresses.

Inlay: Decorative patterns created with pieces of different woods or other materials, which have been set into the surface of wood furniture.

Inner Quilt: A true pillow top mattress will have an inner quilt, which means that the first layers of upholstery are actually covered with a layer of fabric that is sewn to the tape edge of the mattress. Some so called pillow tops do not have inner quilts. These imitation pillow tops have border panels around the perimeter with two tape edges to give the appearance of a pillow top.

Inner Tufting: A very durable method of attaching and combining layers of padding below the quilted cover of a mattress to prevent shifting and settling of the padding layers. This method is rarely used in mass-produced mattresses due to the labor intensive process.

Innerspring Unit: The spring and wire units made up primarily of coils, helical wires and border wires, which is the inside of an innerspring mattress. Some upholstered furniture such as sofas and loveseats can also feature innerspring units.

Inset Tile: A tile with a different design than the surrounding body of tiles.

Insulator: A mattress component that separates and protects the mattress cushioning from its innerspring coils. Common insulators consist of a compressed polyester fiber pad, compressed cotton, or a polypropylene mesh screen.

Intaglio: An illustration or design cut into a surface.

Intarsia: A technique of sinking a decorative design across an entire surface.

International Style: Functional modern furniture style developed in Europe during the 1920’s and 1930’s. The most important origin of this style was Germany's Bauhaus School. Simple lines and an absence of decoration are hallmarks of this design. Popular materials used included chrome and glass.

Iron Bed: Term commonly used to describe beds made of metal that are coated with colored finishes.

Italian Provincial: Loose term applied to furniture of the Italian provinces made during the 1700’s to mid 1800’s. These pieces, although more rustic, copied the elaborate furniture styles of Milan, Venice, Rome and Florence. Later pieces (Late Italian Provincial) were heavily influenced by French design. The pieces feature simplified lines and lack ornate decorations. Very few of these pieces are reproduced today.

Italian Renaissance: Popular through the 1400’s to 1600’s. Italian Renaissance furniture features a very rich appearance and is decorated with carving, inlay, and marquetry. Chairs have a very straight construction and are built with flat runners. Chairs usually have very sturdy stretchers. Tables are very big and elaborately decorated. Tables have stretchers and are rectangular in shape. Most pieces are made of walnut.