The first commercial sex Lily Suck were made of vulcanized rubber and inflated with water or milk to simulate body heat. They were often shaped like women. Today, male dolls account for about 10 percent of the market. The makers of the popular RealDoll line, for example, work with customers to build a body based on reference photos. Many men also assign names and personalities to their dolls, as well as backstories. Doll owners sometimes share candlelit dates and feelings of love with their dolls on hobbyist message boards.

Dolls come in a variety of shapes and sizes, but some are more lifelike than others. Some have built-in heating systems to mimic body heat and breathing. Others have a variety of hair options, from human to synthetic. And some have facial features that can be modified, such as freckles or scars. Typically, base doll models have a certain level of realism, but some companies offer upgrades to make them more realistic, including face-painting, eye color, and the ability to add a piercing.

Maintenance varies a bit, but it’s important to keep sex dolls clean and dry. Some have gel breasts and buttocks that can deform if they’re exposed to moisture for too long. And some dolls require a special hanging system that lets them be suspended when not in use. Many collectors also invest in clothing and accessories, from fetish toys to intimate apparel. In the country of Zambia, where sex dolls are illegal, anyone who makes, owns, or sells them can receive up to five years in prison.