Jens Risom, the Danish furniture maestro who helped bring midcentury modern design to the United States through his work with Knoll Studio, died on Dec. 9 at his home in New Canaan, Conn. He was 100.

His death was confirmed by a friend, Mark Jespersen.

Defined by sharp Scandinavian lines and fused with the rustic aura of Shakerism and American arts and crafts, the armless, affordable chair that became Mr. Risom’s signature in 1942 was one of the first mass-produced modernist furniture pieces introduced in the United States and not Europe.

It both introduced Knoll as one of the world’s most enduring quality furniture brands and helped make great mass design palatable to American consumers, who continue to buy Mr. Risom’s chair 74 years later, in every possible color and fabric, through Knoll and Design Within Reach.

Today, the Museum of Modern Art, the Brooklyn Museum and the Cooper Hewitt, Smithsonian Design Museum all have Risom selections in their permanent collections. Hundreds of high-end vintage dealers collect and sell Mr. Risom’s black leather benches and walnut magazine stands on the antiques site 1stdibs. A recent auction for six vintage wastepaper baskets by Mr. Risom netted $10,625 with Wright, the country’s leading modern design house.