Jockey silks designed by celebrities including Andrew Flintoff and Gordon Ramsay will be auctioned online to raise money for a children's hospital.
The money will be donated to Alder Hey Children's Hospital in Liverpool - the Grand National's official charity - as preparations for the race begin.
Yoko Ono has given permission for a drawing by John Lennon to be featured on one of the silks.
Racing begins at Aintree on Thursday at the start of the three-day festival.
Top Gear presenter Jeremy Clarkson has designed a silk emblazoned with a speed camera, and chef Gordon Ramsay designed a silk with a fish on it in praise of his favourite food.
Racing pundit John McCririck and Sir Richard Branson have also donated designs.
The jockey silks will be on display at the Walker Art Gallery and the World Museum Liverpool from 7 to 30 April.
They will be auctioned online.
Paul Petrie, a spokesman for bookmakers totesport which organised the auction, said: "The Grand National truly captures the nation's imagination and hopefully this campaign can do the same."
Jayne Hauxwell of the Imagine appeal at Alder Hey Hospital, said: "It's a fantastic way to raise funds and awareness for the largest children's hospital in Europe.
"Imagine aims to improve the quality of life for all children in hospital."