Use the word mesh for fabric made of loosely woven fibers. A butterfly net is made of mesh, and so is a window screen.
Some mesh is made from string or fabric, like a fishing net or a mesh sports jersey, while other mesh is metal or plastic, like a tea strainer. In either case, it's woven loosely enough that there are small holes throughout its surface. Another meaning of mesh is "harmonize" or "work well together." In the fourteenth century, it was spelled mesche, and it meant "open space in a net," from the Old English word for net, max.