There are several ways to attempt this delicate technique. First, however, if there is a spider at home in the web, gently blow on it to encourage it to leave!
Spray the web with a dark color of spray paint if you are using white paper or canvas as a background. Spray the substrate with fixative, and bring it up at an angle behind the web. If using paper, curve the edges so the center touches the web first. Then carefully straighten the paper to acquire the silken creation, pull toward you, and let the paint dry. You can also try a white spray-painted web on a dark background.
Incorporate your successful web captures into superb spidery artworks!