Why do some people use eye forms with screws in them?
I saw immortal masks doing a mask sculpture and wondered why they don't use just a eye or ball, and a eye form with a long screw in it instead. I think fourth seal studios sell it.
Eye casting requires casting 2 parts. The core, and the outer clear layer. Once the core is cast it needs to be suspended in the center of the mold for the clear outer layer so clear resin can flow all around it. For this reason most eye mold designs use a bolt in the back of the eye to suspend it at a set height.
For immortal masks, when they cast their masks in silicone they typically don't have the eye as part of it, since a person will be wearing it. They'll often sculpt the character with eyes so they can see the entire character, but then remove any eye forms or sculpted eyes prior to casting. It's usually easier to remove a sculpted eye than an eye form (ball, etc) since that requires pulling out an object that can disturb the surrounding clay.
Ah thank you, I thought it helps when molding or so...