The first thing I heard about cotton ceiling was this (copied from a site through google - there's loads out there on this though, google yourself if you wish):
"Toronto, Ontario (March 28, 2012): Today, the Ad Hoc Coalition Against the Cotton Ceiling (the “Coalition”) submitted a petition with more than 250 signatures to Planned Parenthood Toronto (PPT) to ask the organization to reconsider hosting an event that promotes the sexualization of females.
PPT is sponsoring a March 31 conference in Toronto called “Pleasure and Possibilities.” According to Sarah Hobbs, Executive Director of Planned Parenthood Toronto, the purpose of the conference is to continue conversations that began at an earlier conference entitled “No More Apologies: Queer Trans and Cis Women, Coming/Cumming Together!”
The subject matter of both conferences is specifically sexual in nature. One of the featured workshops is entitled “Overcoming the Cotton Ceiling: Breaking Down Sexual Barriers for Queer Trans Women.” The workshop facilitator has defined the “Cotton Ceiling” as follows:
The cotton ceiling is a theory proposed … to explain the experiences queer trans women have with simultaneous social inclusion and sexual exclusion within the broader queer women’s communities. Basically, it means that cis queer women will be friends with us and talk day and night about trans rights and ending transmisogyny, but will still not consider us viable sexual partners.
The term cotton ceiling is a reference to the “glass ceiling” that second wave feminist identified in the workforce, wherein women could only advance so high in the workforce but could not break through into positions of power and authority. The cotton represents underwear, signifying sex."