Half masks are great. Particularly with body suits like from Smitizen or Immortal.
Although the definition of "half" varies somewhat from company to company. In terms of realistic masks, it's easiest to think of them of short, medium and long, and amount of "neck pop" experienced. (gee, I use such technical terms, don't I?? <grin>)
For this discussion, I am only considering half masks that offer a "full-360" illusion. Masks that have a fabric back are excluded, for obvious reasons. If I've left any company out, please let me know and I'll be more than happy to discuss.
SHORT HALF
"Short half" can best be illustrated by Immortal's line of half-masks. These tend to have the least amount of coverage on the neck itself and could be considered more of a "full head" mask. This is quite understandable and in line with Immortal's background in the haunt/performance space, where long-term comfort is of prime importance, and most delineations between the edge of the mask and the start of the skin can be covered with makeup or costume accessories. Another example of a short half mask is Studio135's "Dwarf". I had an Immortal "Craterface" and coverage was perfect with a regular dress shirt collar.
LONG HALF
A good example of "long half" half-masks is Studio135's "Knuckles" mask. This mask has full coverage of the neck with what could be considered a "micro-bib" on the front and back. My "Knuckles" works perfectly with a polo shirt. However, there is an annoying tendency for the bib to "pop" when moving your head from side to side. It is perfect underneath a torso as the silicone neck of the torso will hold it in place.
MEDIUM HALF
An excellent example is Metamporphose Masks "Troy" model. This type of half-mask has near-full coverage of the neck area, but lacks the micro-bib of the long-half types.
WHAT IS NECK POP??
Think of the different shirts you wear - t-shirts, hoodies, sweatshirts, zip-ups, turtlenecks, polos and dress shirts. The collars on each of these are of different heights - and shows different amount of neck skin in the front. "Neck pop" can be thought of as the lack of realistic coverage over the height of the collar combined with natural movement of the head.
Short half-masks have a high degree of neck pop on t-shirts and sweatshirts, with the amount of neck pop decreasing as the collar height grows. Polo shirts can be a mixed bag, depending on the mask company, with regular dress collars or higher providing the best coverage.
Long half-masks are a bit of a contradiction. While they can be worn with a t-shirt or sweatshirt, average head movement tends to dislodge the micro bib and ruins the transformation illusion unless a silicone adhesive is applied. These masks are probably one of the two of the best type for body suits where an intervening accessory (e.g. leather collar or a scarf) is not available. Polo shirts or anything with a higher collar works well with this type.
Medium half-masks are the happy medium (pardon the pun) between the two. Head movement does little to affect the transition between mask and skin, and t-shirt and sweatshirts can almost be worn with the illusion being maintained (at a distance vs. close up), with any other collar providing sufficient coverage. The medium-half mask is the other type that works well with body suits without using an intervening accessory.
I'll be doing a full review of the "Troy" mask, so stay tuned!