Rosamind Julius: Award-winning furniture maker who helped introduce post-war Britain to modern design

Rosamind Julius was one of the standard-bearers of British post-war contemporary design.

Working for her family firm, Hille, she and her husband Leslie transformed the company into one of the country's leading manufacturers of cutting-edge modern design.

Hille was originally set up in an East End workshop by Rosamind's grandfather Salamon, a refugee from Imperial Russia. Although he initially ran it almost as a hobby, when his family managed to escape the pogroms and join him several years later, he turned it into a full-time business and quickly established a reputation for high-quality reproduction furniture sold through outlets such as Waring & Gillows, Maples and Heals. After the Second World War, his daughter Ray (Rosamind's mother) joined the company and was to take over much of the day-to-day running of the business. An excellent draftswoman, she was also responsible for most of the company's post-war designs.

Rosamind was born Rosamind Goldman in 1923. When her mother formally took over full control of Hille in 1932, Ray decided that the family name should be changed back to Hille. After school (North London Collegiate) Rosamind started training as an architect, but her studies were interrupted by the war, when she joined the WRNS and eventually served on the staff of Louis Mountbatten. During the war she met Leslie Julius, then a Captain in the Royal Artillery, and they married in 1944.

At the end of the war, Rosamind and Leslie joined Hille. The company already had a well-established commercial relationship with John Stuart inc, in New York and, the couple crossed the Atlantic to sell their William and Mary furniture designs. It was a trip she described as a "revelation". Unfettered by the wartime austerity of the UK, new buildings were rising throughout the city and inside them was bright, modern furniture.

Although Hille continued to export their Chippendale breakfront bookcases in considerable volume, on a second trip to New York in 1949 they saw the award-winning entry for a Museum of Modern Art competition which had been jointly designed by Robin Day and which had been selected from 3,000 entries from over 30 countries. On their return to London, they sought him out, and the first result of their collaboration was furniture for the Festival of Britain in 1951 while, in the same year, their entries won gold medals in the Milan Triennial. The partnership endured for another 30 years.

But their new designs did not meet favour with the established conservative retailers of the time. The Daily Sketch asked of chairs designed by Day and Charles Eames: "What are they aiming at? Is the whole thing a giant leg-pull?" Undeterred, Rosamind and Leslie decided to bypass retailers and aim their products directly at architects, specifiers and their clients. In 1952 they established the first of their showrooms in Albemarle Street and, although Rosamind described the early period as "a tremendous struggle", the Hille showroom was to become her undisputed kingdom for more than 20 years. Others were later added in Birmingham and Manchester.

The Juliuses shared with Day a belief that the Holy Grail of furniture would be a simple mass-produced, all-purpose chair. Initially they turned their attentions to moulded plywood, a material developed during the war for aeroplanes. The result was the Hille Q-Stack, which Rosamind and her growing sales team were able to sell directly to schools and auditoriums. The experience they gained during the chair's manufacture allowed them to experiment with more ambitious plywood designs which became the company's staple for a decade. Many of these are now highly sought-after and sell for increasingly large amounts of money.

But plywood was still limited, both in volume and in the creation of compound – three-dimensional – shapes which were essential for comfort. Polypropylene, invented in 1954, was to be the answer. A single mould could produce a chair shell every minute and a half, and its cost was measured in pence. In 1963 the world's first polypropylene chair was launched from Rosamind's Mayfair base. The Architect's Journal wrote that it "will certainly prove to be the most significant development in British mass-produced design since the war". The range has since gone on to sell in millions worldwide, and the original chair is still in production today.

Rosamind turned her Albemarle Street showroom into a Mecca for visiting architects and designers, both from the UK and from overseas. She related to people instinctively, displaying a warmth and empathy that beguiled even the most cynical and she added a glamour to the design world which few could resist. The annual Hille Christmas party became a measure of one's standing in design circles and it was said that had a bomb fallen on it, much of Britain's design community would have been wiped out.

Rosamind maintained the company's emphasis on exports by winning the contract for furnishing the Skidmore Owings & Merrill's Istanbul Hilton. This was followed in the UK with a contract to furnish the new Gatwick airport. Brian Henderson, the architect, described them as "Goodies in a world where there weren't many about". The international connection was reinforced when they were appointed as licensees for the American companies Herman Miller and then Knoll. This led them to manufacture furniture by most of the 20th century's best-known designers, including Charles Eames, Florence Knoll, Eero Saarinen, Mies van der Rohe and Marcel Breuer.

With launch of the polypropylene range, Hille became licensor and eventually agreements were signed for its production in over 50 countries. This added to the increasingly international circle of friends and associates who passed through London and enjoyed Rosamind's enthusiastic hospitality. Among the designers to produce award-winning designs for Hille was Fred Scott, who was given free rein to experiment with a new plastic, polyurethane; he came up with a range of sculptural seating which was considered ahead of its time, but is now highly sought-after. The partnership produced their most iconic design, the Supporto range of seating, one of the most elegant chair ranges to be designed in the second half of the 20th century.

A long-time member of the board of the International Design Conference in Aspen, in 1986 Rosamind co-chaired, along with the designer Kenneth Grange, a celebration of British design. This was attended by a galaxy of leading artists and designers ranging from Norman Foster to David Hockney. The company's contribution to British design was also recognised by a retrospective exhibition at the Victoria and Albert Museum in 1981. Roy Strong, the V&A's then director, said that the company's name "was a watchword in all circles where design is taken seriously".

Rosamind and her husband were jointly awarded the Royal Society of Arts Bicentennial Medal in 1972 for "exceptional influence in promoting art and design in British furniture". She was made a Honorary Fellow of the Royal Institute of British Architects in 1984 and a Senior Fellow of the Royal College of Art in 1998.

Although the last years of her life were blighted by dementia, she remained cheerful and continued to revel in the company of others, as she had done throughout her life. Rosamind Julius is survived by her daughter Corinne Julius, a journalist and broadcaster.

Rosamind Goldman (Hille), furniture maker: born 30 November 1923; married 1944 Leslie Julius (died 1989; one daughter); died 19 May 2010.