Sofa Cushion Dense Upholstery Foam (Danforth and Greenwood)

Looking for high density upholstery foam. New or repurposed from a couch bench seat cushion. Trying to recover the seats of 2 chairs but need tougher denser foam that springs back. Softer foam flattens out into a pancake. If your getting rid of a couch or sofa that has cushion seats that would be appreciated. And maybe save half of it from landfill.