Over the decades, Jacqueline Kennedy Onassis wrote notes to some of her favorite designers. She even drew sketches of pieces she wanted.
This weekend, some of these letters will be auctioned off in West Palm Beach, Florida.
CBS News correspondent Vicente Arenas got an inside look at some of those highly sought-after items, and at the late first lady's flair for fashion.
Elegant, sophisticated, graceful: just some of the words that come to mind when describing Jackie O.
Her notes to her designer and to her interior decorator, being auctioned off by Rico Baca, show just how closely she cultivated her signature style.
"She's inviting these people into her life, to get close to her, close enough to give her what she wanted," Baca said.
He said those notes offered designers a look into a very private part of her life.
"She would have to be a little bit vulnerable," Baca said.
No detail escaped her eye. In one note for Bill Hamilton, then design director for Carolina Herrera, she wrote that pockets were in and boxy shoulder pads were out.
"If the collection had 90 pieces, she might like five suits, and we would cut those in different fabrics and colors and there were certain colors she wouldn't want to wear -- one of them being black," Hamilon said.
Onassis wrote she was "so sick of [seeing] everyone constantly in black -- like Mediterranean villages where everyone is in mourning for 20 years."
She drew a sketch herself that Hamilton then turned into a design. The final product was a brown velvet suit, which made her very excited. Onassis was often very hands-on during the process.
"We would have lunch at my desk and she would pull out a peanut butter and jelly sandwich that she carried in her bag and have coffee," Hamilton said.
For her home, she worked with interior designer Richard Keith Langham.
"She had a hand in everything there," Langham said. "Whether she would be dictating exactly what sort of velvet she wanted on a chair, exactly what sort of cording she wanted to trim a pillow."
In one note, Onassis told him: "I wasn't mad about the black chairs. Too heavy, I'm afraid -- so do keep looking."
But most of the letters, many written in her signature blue stationary, were actually thank you notes to both men, letting them know how happy she was with the results.
"All these notes are special in the sense that she took the time to sit down and write something in appreciation," Baca said. "A thank you note is a form of respect."
Onassis had other ways to show she was grateful.
"She gave me an original 1963 edition of her White House Guidebook, and she inscribed that to me: 'Perhaps this great house will know your touch one day,"' Langham said. "And as a young decorator, that was sort of awe inspiring for me."
Fourteen photos taken by Bob Davidoff, a long-time photographer for the Kennedy family, are also part of the auction.
"I can't imagine anyone who wouldn't want them," Baca said.
More than a 1,000 people are expected to take part this weekend. Each lot, some containing two or three letters, is said to be worth $800 to $1200.
Although some would probably argue Onassis' gratitude is priceless.