Silica gel packets. You probably know that those little silica gel packets are meant to preserve freshness. There’s no magic here. The packets have silica gel beads inside that absorb humidity in an enclosed environment, protecting products from dampness.Typically, when silica gel packets absorb water, of which they can contain up to 40 percent of their weight, they're no longer effective. However, you can try to restore them by drying them out again in the sun.