Sydney seamstresses who fell in love with Meghan Markle's dress recreate it in 10 hours.

Replicating Meghan Markle’s royal wedding dress seemed relatively straightforward for two Sydney seamstresses until the bride stepped out of the car at St George’s Chapel with a five-metre, heavily-embroidered veil.

Like millions of others around the world on Saturday, Elizabeth Alexandrou and Tessa Rankin were glued to their television screen as the former Suits actress made her way to Windsor Castle to marry Prince Harry.

Surrounded by fabrics and patterns, the dressmakers had already a basic fitting with their model.

“We just sat there and patiently watched for the reveal,” said Ms Alexandrou, who produced the one-off creation in approximately 10 hours for fabric and haberdashery chain Spotlight.

“We sort of got an idea through the car with the neckline but once she got out, we started sketching.”

The new Duchess of Sussex wore a pure white, open bateau-neck gown with three-quarter length sleeves, a sculpted waist and an A-line skirt, fashioned from double-bonded silk cady, with a triple-silk organza underskirt.

Designer Clare Waight Keller, the artistic director of iconic French fashion house Givenchy, was behind the minimalist, haute couture gown.

It was accessorised with a billowing veil embroidered with flowers from each of the 53 Commonwealth nations, including wattle for Australia, plus two of Ms Markle’s own favourites, Wintersweet and the California poppy.

The sparkles were reserved for the bride’s head, where Queen Mary’s 1932, diamond filigree bandeau tiara held the silk tulle veil in place.

"We were very surprised but it was very classic and there was that comment that she didn't want to upstage Kate (Middleton)," Ms Alexandrou said.

"I loved the veil with the lacework on the edge, it was really a lovely dress and really it suited her well."

While Ms Markle's dress is thought to have cost into the hundreds of thousands of dollars, the Spotlight creation, using a handful of patterns and more than 30 metres of fabric and veiling, cost $700.

The seasoned dressmaker said the structure of the bodice and sleeves was fairly common but it was "unusual" for the veil to be so prominent beyond the train, which is not something "normal brides" choose.

She said while Ms Markle's pure white veil offset the brickwork of the chapel and the steps, they made their replica gown from an off-white duchess satin with an off-white veil to accent the dress.

"We couldn't recreate the embroidered Commonwealth emblems but we just put some lace around it to be representative," Ms Alexandrou said.

"It also added to the impact of the final reveal, having the veil, as the dress needed something else to really have the bridal feel to it.

"The time to get it perfect was hard but we gave it a red hot go."