One of the interesting quirks of the fashion industry is that sometimes its most pure incarnations are not wearable. Haute couture is often unwieldy and more conceptual art than clothing, and this element creates a market for extreme and unwearable pieces that amp up the drama during the shows. Case in point, the headdress.

These aren't really hats – even when ready-to-wear creations from milliners like Stephen Jones and Philip Treacy are super sculptural, fundamentally, they're still wearable. An extreme headdress takes the idea of a hat and then takes the 'idea' more literally than the 'hat'. You can wear a hat, but you haven't really got a shot at wearing these. Not because they aren't available, but because they're all like, 'not if I wear you first'.

They are, in fact, available – you can buy Gaga's lip headdress from 'Bad Romance', if you feel like it. But beware! We don't know what happens when you take a headpiece out of its native runway/editorial/music video environment. Some barriers between the real and the hyperreal should just not be crossed! Wormholes could open up, do you hear?!

Take this image. Charles Le Mindu wants you to appreciate his pieces, but not as though they were part of an outfit, and that's why she isn't wearing one. Le Mindu also did Gaga's lips.

Another milliner to dress Gaga's head is Nasir Mazhar, who accessorized Louise Gray's new collection with balloon head dresses.

Mazhar's balloon ladies may want to avoid standing next to models in Shilpa Chavan's helicopter head piece.

Though they could take shelter from the winds in Chavan's nearby tent...

Finally we have Michael Howells, the production designer and art director who also produces OTT headgear for catwalks. Here is his squid headpiece, part of a series for a Dior show from 2007.