Every mother knows that dreaded moment when a child makes a grab for her best dress with decidedly sticky fingers.
But Diana, it seems, was never precious about her glorious gowns, especially when her young sons toddled up for a hug.
Shown here for the first time are what historians believe to be William and Harry's tiny handprints preserved in the fabric of one of her favourite dresses – three decades after their mother first wore it.
Marks from the princes' tiny hands are captured on the skirt of the Victor Edelstein gown
Seeing what appears to be a small cluster of fingerprints on the skirt, it is all too easy to imagine William, three, and his one-year-old brother, Harry, clinging to their mother's legs as she got ready
The gown, made by Victor Edelstein in 1985, was commissioned by the princess to wear for private palace events. As a result, it was never seen in public until it was auctioned off to a private bidder in 1997, when Diana decided to sell some of her outfits for charity.
Now it forms part of a dazzling exhibition at Kensington Palace, her old home, which features 25 of Diana's most famous gowns.
This dress is made from an exquisite bottle green silk velvet, a notoriously difficult fabric to maintain.
Both heat and moisture – particularly when there are grubby little hands involved – can make indentations in it which, according to experts, would survive the test of time.
Seeing what appears to be a small cluster of fingerprints on the skirt, it is all too easy to imagine William, three, and his one-year-old brother, Harry, clinging to their mother's legs as she got ready.
An exhibition opening at Kensington Palace later this month will celebrate Diana's fashion legacy 20 years after her tragic death. Pictured: a curator makes the finishing touches to a Bill Pashley suit (right) worn by Diana on her honeymoon in Balmoral (right)
A more daring dress is a sleeveless above the knee design by Catherine Walker, which Princess Diana wore to a Christies Auction Gala in New York in 1997
Princess Diana wore this Catherine Walker black halter-neck at Versailles in 1994 and will also be on display at the palace
A member of staff poses with a 1990 Catherine Walker grey silk satin dress with simulated pearl embroidery during a preview for the forthcoming 'Diana: Her Fashion Story'
Each of the outfits in the exhibition will be exclusively previewed in a major series in the Mail which starts tomorrow with an eight-page supplement.
The display has been organised by Historic Royal Palaces, the charity responsible for the upkeep of some of our most important royal residences. Its curator of historic dress, Eleri Lynn, said: 'How incredible to think these teeny, tiny prints from the princes' little hands could have lasted all this time.
The dress was a favourite of Diana's and worn many times in private.' Diana: Her Fashion Story opens at Kensington Palace on Friday, February 24.
Entry is included in the palace admission fee. For more information and tickets visit hrp.org.uk/Diana
Diana was photographed wearing the stunning gown by Mario Testino in the last photo session before her death
Another piece sure to be recognised by visitors is an Emanuel pale pink chiffon blouse with satin neck-ribbon worn during Diana's first official portrait in 1981 captured by the late Lord Snowdon
This beaded Versace silk gown (left) was worn for a Harper's Bazaar cover in 1991 and the Catherine Walker green silk velvet evening dress with velvet and diamante buttons (right) was worn for Diana's Vanity Fair photo shoot with Mario Testino