The collage containing five fabric off-cuts from the gown and one from one of the bridesmaid's sashes is open for bidding at PFC Auctions, a Guernsey-based online auction company.
The gown worn by the late Princess of Wales on her wedding to Prince Charles in 1981 was created by designer Elizabeth Emanuel, the Daily Mail reported.
Elizabeth gave the fabric off-cuts to the family who cared for her children during the two weeks prior to the Royal Wedding as a token of her appreciation.
The off-cuts have been framed with a sketch of Diana's gown from the official press release and a handwritten letter from Elizabeth Emanuel, thanking the family for minding her children in the busy run up to the Royal Wedding.
The dress was made of 25 yards of silk taffeta, 100 yards of tulle and 150 yards of netting for the veil.
The 25-foot silk train is the longest in Royal history.
Diana's five bridesmaids also wore dresses of ivory silk, modelled closely on her gown.
Diana kept with tradition and wore an old antique lace, new silk, a borrowed tiara and a small blue bow, sewn into the waistband of her dress.
"This is a unique memento of Charles & Diana's wedding which was watched on TV by an estimated 750 m people worldwide.
This collage is the perfect opportunity for collectors to own such a personal item from the wedding of the People's Princess," Kylie Whitehead, PFC Auctions Spokesperson, said.
In may, a scrapbook of Prince Charles and Princess Diana's Royal Wedding made by Elizabeth Emanuel sold for 3,194 pounds at PFC Auctions.