Nicole Kidman's favourite fashion item is ''black tights''.

The 48-year-old actress has confessed her love for opaque stockings, insisting that she's over the moon they came into fashion.

When asked what her favourite fashion trend of all time is, Nicole simply replied: ''Black tights''.

The 'Moulin Rouge' star also revealed her biggest fashion icon is Lisa Fonssagrives, the late Swedish beauty, who is widely considered to be the first ever supermodel.

Speaking to Vogue.com, Nicole said: ''(My fashion icons) are probably all of the women that (the late photographer) Irving Penn photographed, but especially his wife Lisa.''

The Hollywood superstar also described what she wore to her prom - which Aussies refer to as a 'formal'.

Nicole said: ''I wore a vintage black flapper dress.''

The 'Australia' star has previously said her children are her biggest fashion critics.

Her two daughters, Sunday Rose, six, and Faith, four, always tell their mother what they think of her outfits especially when she is getting dressed up for red carpet events, and even told their mum she looked ''too tall'' in her high heels, when she was going to co-host the G'Day USA Gala and AACTA International Awards in Hollywood earlier this year.

Nicole - who was accompanied by her husband Keith Urban - said at the time: ''My daughters were like, 'Hmm, you're too tall.' They don't like it when I wear high shoes. I keep telling them they're going be tall one day.''