Cloth napkin, eh? Instead of paper napkin, eh? Let's see, the cloth napkin, made of cotton, requires bulldozing and laser-leveling square miles of Sonoran Desert, eradicating all the native flora and fauna, and creating a monoculture of cotton, and its pests. To irrigate these otherwise lifeless fields, we've dammed the Colorado river, and others, drowning spectacularly beautiful canyons, and requiring coal-fired, polluting, power plants to create electricity to power pumps to move the irrigation water to these ecologically dead cotton fields.
Whereas, the paper napkin can be made of deciduous tree fibers, renewably grown and economically harvested in temperate climates, such as Michigan's, without irrigation, or adverse impact on the environment, while providing excellent habitat for various fauna in its various stages of growth.
I've recently purchased some picnic utensils that purportedly are made from some corn extract, biodegradable, photodegradable, etc.
Your kid's teacher is evidently an ignoramus, in need of correction.