Melissa Erdman has a killer recipe for vomit.

“Mixed-fruit oatmeal,” she said.

Ms. Erdman knows from bodily fluids. As a freelance props master (or “prop tart,” as she calls herself), her job is to buy furniture, make accessories, whip up batches of blood or do whatever else it takes to make sets look and feel as authentic as possible. Ms. Erdman was one of about 50 props people who gathered on Friday night at the Public Theater for an informal meeting that gave attendees a chance to network, watch demonstrations and exchange insider tips on the latest techniques in an area of theatrical design that often goes unnoticed and unheralded.

“It’s kind of the stepchild of theater,” said Faye Armon, a properties coordinator who works often at Lincoln Center Theater.

Theatergoers probably understand what costume, set and lighting designers do. Their work can be eye-catching, and their names appear on a program’s main credit page. They get their own Tony Award category. But a props master?

“Picture moving into a new apartment, and everything is bare,” explained Jay Duckworth, the Public’s properties master and the organizer of the gathering, now in its fourth year. What a prop person does is “make that apartment represent you or your girlfriend or your grandmother,” he said, “everything from the lights to curtains to pillows, to ashes in an ashtray.”