Just In Case You Wanted To Know
I'm not entirely sure if including this section is a good idea. Head sizing, or more accurately hat sizing, isn't divided up between male and female. It's a hat industry thing whereby they take the head crown measurement and arbitrarily assign a size to it depending on which country you come from. So what do hats have to do with stretch pattern making? Read on...
There is a whole industry out there making full face hoods, be it for neoprene diving masks or Lycra kids’ ballet animal costumes or even some highly complex theatrical costumes. To my dismay they all use the hat sizing system. This system makes no reference to face diameter or the sizing of features, like chin width ... obviously because they have no part to play in hats. So why use it when designing hoods? Well apparently they must all think hoods are still hats. Thankfully, the other head measurements are relatively proportional to crown circumference in as far as hood design goes so nobody has really noticed the problem unless their nose or chin are particularly large. The average male crown is 58cm and average female crown is 55cm. The Asian chin and nose are usually significantly smaller for equivalent crown than their western counterparts.
I found this photo somewhere in my travels and have no idea where it came from. I don't know if it's a once off thing or available for commercial sale but it's so cool I just had to include it. If you're the one making it, or know who does, please let me know and I'll link it in to you. It's a neoprene diving hood ... I have no idea if anyone would use it for that, but if they did I'd bet they'd have less trouble with sharks.
Of course custom pattern makers only need to consider actual measurements, but those designing hoods and masks will need to adapt some kind of system (usually dictated by the designer).
Face is a full diameter measurement taken at right angles to crown circumference when looking side on. The face measurement is, coincidentally, the same as the crown when we're looking at averages; however there can be considerable variation toward either end of the range, so always take it no matter how consistent you might think it is. The neck measurement is the smallest diameter of the neck.
People making latex hoods for fetish wear will obviously need to take a lot more measurements if they're looking to be anatomically correct on facial features. In this case things like position of the eyes, nose and mouth are critical to the function of the garment. The nose is often made as a separate pattern piece and often serves to locate the garment so it needs to be very accurately positioned.