The most expensive sex dolls (approximately $1,200 and up) are usually made from silicone (usually above $3,000 at 2016 prices) or thermoplastic elastomer known as TPE (below $3,000). Dolls made of either material can be very lifelike, with faces and bodies modeled on real people in some instances, with realistic skin material (similar to that used for movie special effects), and with realistic (or even real) hair. These dolls usually have an articulated PVC or metal skeleton with flexible joints that allows them to be positioned in a variety of positions for display and for sexual acts. Silicone or TPE dolls are much heavier than vinyl or latex inflatable ones (which consist mostly of air), but are roughly half the weight of a real human being of comparable size.
It also can retain warmth, so if you decide to heat it up a little bit, it definitely has that potential. However, you shouldn’t try to give it hot baths or submerge it too much, since often, this can mess with the skin, breaking it down and ruining the doll. But, if you want to mimic the warmth of a body, then you can use this, since often the fact that it is way more sensitive does help with this.
Some of the first sex dolls were invented by Dutch sailors in the seventeenth century who would be isolated at sea during long voyages. These masturbatory dolls, referred to by the French as dame de voyage and by the Spanish as dama de viaje, were made of sewn cloth or old clothes and were a direct predecessor to today's sex dolls. The Dutch sold some of these dolls to Japanese people during the Rangaku period, and the term "Dutch wives" is still sometimes used in Japan to refer to sex dolls.
Now, TPE stands for thermoplastic elastomer, which is essentially a mixture of polyvinyl chloride and silicone. This is a type of skin that is very soft, and it mimics the feeling of human skin. TPE is way more realistic in feeling and it definitely mimics the feeling of human skin. It also is much cheaper than silicone alternatives, sometimes even hundreds of dollars cheaper. TPE also allows you to move the doll around in various ways, since it has more flexibility. TPE dolls don’t really need to be bathed, but you can, just be mindful of the water. It also is hypoallergenic as well.