Advantages – As a flexible casting material in special cases but normally only when applied in thin layers and better using an absorbent mould such as plaster (latex is an ideal material for the absorption casting method). Also ideal for creating flexible ‘skin’ surface casts. Good detail reproduction. Relatively inexpensive (c £11 per litre). Can be used as it comes, no mixing needed. Durable and long-lasting, with a surprisingly high tear strength. Can be thickened (special additives available). Latex is readily available (many suppliers, inc. hobby and art shops). No serious health&safety issues. Can be coloured (using small amounts) with any water-based paint.
Not so good – Cannot be poured as a ‘mass’ into a non-absorbent mould (such as silicone) because it sets by evaporation of water content .. it will never dry! Can only be applied in layers, each of which needs to dry first before applying the next. Drying is slow unless mould is absorbent. Will shrink up to 10%! Surface painting of dried latex poses some problems (best methods are either to mix acrylic paint with Prosaide or use Humbrol enamel paints). Latex casts need a good dusting of talc to stop them sticking together. Latex is not compatible with petroleum jelly i.e. Vaseline, so this cannot be used as barrier/release agent.
For this mask, I think a solid mask is needed to support the structure of it rather than a flexible latex mask. – jesmonite?