I have a Tumbleweed composter and last year when brown material was scarce, I shredded many newspapers and used them in the composter. I won't make that mistake again. They just balled up in large clumps compared to the rest of the composted material. Looked like compost on the outside but newsprint on the inside. I put this composted material on the garden last fall and when I tilled the bed just last week, I'm still tilling up clumps of newsprint about 3" in diameter that still didn't decompose after spending at least 6 months at which time I hand dug the bed turning the compost under the soil. The best source of brown material I found so far is fallen leaves in the fall but my problem is, where do you find good brown material to ad to the composter during the summer months? Lost of green material with all the grass clippings but very little brown material.
Rich