To spread forth and multiply, fungi — including the familiar button, portobello and shiitake mushrooms — shoot their spores into wafting breezes.

A new paper published Wednesday helps explain how fungi aim the spores in the right direction. Scientists at Duke University constructed larger spores out of plastic spheres and then used an inkjet printer to build water droplets, which are key to the launching mechanism.

The artificial spores and droplets in the experiment were about 10 times the size of ones in nature. That slowed down the motion so it could be captured on video. “With that system, you get what the real spore is doing,” Chuan-Hua Chen, a professor of mechanical engineering and materials science at Duke, said.

Dr. Chen and his colleagues describe the findings in The Journal of the Royal Society Interface.

“This new paper really is an almost miraculous proof of principle,” said Nicholas P. Money, a professor of botany at Miami University in Oxford, Ohio, who was not involved with the experiment.