February 10 is World Umbrella Day, an occasion not typically marked by raucous celebrations but one always remembered in Melbourne's east.

In East Malvern is the former home and studios of Karl and Slawa Duldig, which is now a museum of their impressive artwork including bronzes by Karl, a renowned modernist sculptor.

It also holds an early prototype of an Austrian-invented folding, collapsible umbrella.

Slawa Duldig invented and patented the umbrella design in 1928 when she was still Slawa Horowitz.

Both Polish-born, she and Karl met while studying sculpture in Vienna.

The two would frequently draw together on Sundays in the surrounds of the Kunsthistorisches Museum.

Art students would regularly go to Kunsthistorisches Museum to draw renowned works of fine art. ( Wikimedia Commons: Public Domain )

Their daughter Eva, who founded the Duldig museum, said it was on one of the drawing excursions that Slawa came up with the idea for the folding umbrella.

Writing before her death in 1975, Slawa recalled that it was a rainy May day in 1928.

"I armed myself with a big umbrella and muttered to myself: 'Why on Earth must I carry this utterly clumsy thing? Can't they invent a small folding umbrella which could be easily carried in a bag?'"

She went home and spent some time coming up with her design.

A prototype was built with parts from watchmakers, and she made sure not to buy too many parts from any one place.

"She didn't want anyone to cotton on that she was doing this umbrella thing," Eva said.

The 'magic umbrella'

Slawa obtained a patent for her invention in 1928 and successfully licensed the design to manufacturers in Austria and Germany.

Patents for folding, telescopic umbrellas date back to at least 1896 but Slawa's improvements were elegant.

She simplified the folding mechanism, allowing the whole umbrella to be smaller and more practical.

Slawa Duldig kept her folding umbrella secret until she had secured a patent. ( Supplied: Duldig Studio Museum )

The umbrella went on the market with an unusual name.

"The little umbrella was called Flirt, which was very with it," Eva said.

"It was still seen as quite a luxury item; it was beautifully finished and made out of nice materials."

The Flirt was featured at the 1931 Inventor's Fair in Vienna, with the press describing it as "the magic umbrella of the sculptress".

Slawa married Karl that same year and her business helped to fund their new life together.

"She was able to furnish the whole house with this beautiful customised art furniture made by a very well-known firm in Vienna," Eva said.

Secret stowaways

Slawa gave birth to Eva on February 11, 1938, one month before the Nazis marched into Austria.

The young family fled via Switzerland, but under pressure from the Nazis Slawa sold her rights to the umbrella to company Brüder Wüster.

She was, however, able to evade the authorities and secretly put the umbrella prototypes into storage.

Prototypes of the Flirt umbrella were among possessions Slawa Duldig hid from the Nazis. ( Supplied: Driftwood by Eva Duldig )

Eva's book Driftwood tells the remarkable story of how her parents escaped Austria and wound up in Australia while keeping their possessions hidden from the Nazis.

She said she applied an important lesson from her mother while writing their history.

"Even though I was writing the book for 40 years, I didn't tell anyone ... I kept it quiet until it was out."