Rosin Industries Rosin Bags are made of 100% food-grade and dye-free nylon mesh to ensure a clean and solvent-free extraction. They range in micron from 25?160. Smaller microns, 25 and 45, are ideal for finer material, while the 90 and 160 work best for coarse material. Each bag is 2.5 in x 3.25 in and can hold up to 14 g of material. The bags feature top-quality inside out stitching and are rated for temperature up to 350ø F. Each package contains 10 bags.