The spare gown was made in case the original design was leaked to the public.

Princess Diana and King Charles on wedding day

Photo: Princess Diana Archive/Getty Images

It’s hard to imagine the late Princess Diana in any other wedding dress than the ivory and silk taffeta number she wore on her big day. But according to her designer Elizabeth Emanuel, Princess Diana’s wedding gown could have looked slightly different.

In an interview with Hello! magazine, Emanuel, who designed the dress alongside her ex-husband David, revealed there was a backup gown made for the royal wedding; she also shared several never-before-seen images (including a sketch and in-progress photos) of the garment with the outlet. “The spare wedding gown was made just in case the secret of the real dress ever got out. Fortunately, it was never used,” she said. “The dress was made in pale ivory silk taffeta with embroidered scalloped details on the hem and sleeves. Tiny pearls were sewn on the bodice.”

Back of Princess Diana's wedding dress

Princess Diana Archive/Getty Images

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Sketches of the dress show that it was similar in appearance to the gown Princess Diana wore on her wedding day, including a V-neck, three-quarter sleeves, and a wide princess skirt. “People always ask you what it was like,” said Emanuel. “It was similar in certain respects and both had the big skirt, but everything else was different.”

A few details set the spare dress apart from the one Princess Diana wore during her nuptials to the Prince of Wales (now King Charles III). Her silk taffeta gown had dramatic puffy sleeves, while the backup dress featured more fitted ones. Additionally, the ruffle details on the arm openings and neckline were more understated than those on the spare gown.

The extra dress was created largely in case the original design was leaked to the press before the wedding day. But the designers also made an extra skirt in the event that Princess Diana spilled something on it during the festivities. The backup ensemble was never finished and its whereabouts are currently unknown. “I don’t know where it went. It just disappeared,” Emanuel told Hello!.