How would you measure a head for a crown?

[Lukas Exemplar]

How do you guys recommend I should go about measuring someone's head if I were to replicate this crown. I assume with a measuring tape, but what do you measure on the head to make sure it will fit and stay on the head?
?

 

[chrisnupp]

 

[Lukas Exemplar]

View attachment 776654

Is this better than measuring more straightly and less slantedly? The crown seems to be fairly low and close to the brow of the characters in the images (and actually drooping down almost over the nose on the elderly monarch. (a result of it not fititng his head shape in the story it's from, I believe.)

 

[Darth Lars]

You should fit it not only to the circumference but also to the shape of the head. Maybe make a life-cast and sculpt on that.

I once made the basic shape of a half-crown for a Padmé "Travel Gown" crown from Star Wars Episode 1.
I first tried out several templates out of card, each one with hooks around the back of the ears.
The winning shape was cut out of HiPS sheet and that was heat-shaped until it had the right curvature. The detailing was then built on top of that by another person.
The crown sat on top of the ears and was held on with elastic, with the elastic hidden by a cowl.

The way I heat-shape HiPS is that I heat it a little in the oven or with a heat gun, then I bend it with my bare hands more than the intended curvature while it cools. When I let go it should rebound to a shape. If that is not the intended curve, I repeat. It can take half a dozen repetitions until it is just right.
... and have a window open for ventilation or do it outdoors.

 

[chrisnupp]

That part of the head is the widest part, anything smaller in measurement would cause the crown to ride up, anything bigger would cause it to droop. What you want to do is line up the crown and sculpt it based on that measurement. you can sculpt it to go down to the brow, but if you keep that measurement it will ensure that where that sculpt is made it will stay. the easiest way to sculpt it would be a lifecast of your actor, but if you dont have that, i'd take that meaurement i showed, and build up styrofoam or manequin head to be proportional to that measurement.