I stand corrected! See my previous post Toilet designed by a fashion designer.
It does appear that the 9-heads proportion used in fashion design drawings is a realistic representation of women in real life. As French model Isabella Caro demonstrates below (red lines are my additions; 10-heads if you count feet on tiptoes.)
Image from connect.in.com
Isabelle Caro did a whole series of controversial anti-anorexia ads in 2007. She died today aged 28.
Here are two "how to" templates fresh off the Internet:
Left: http://serpentsdoves.wordpress.com/
Right: http://www.howtofashiondesign.com/ (PDF)
In case you missed the note of sarcasm in the opening paragraph, I continue to haves serious doubts about the ethics and practicality of using distorted and unrealistic fantasy drawings in what is supposedly a serious design profession.
