Best Foam Cushion serves clients throughout the entire Minneapolis-St Paul area. Best Foam Cushions specializes in foam cushion replacement. Call us today Factors That Affect Cushions Foam density refers to the weight, in pounds, of a square foot of foam. Foam density isn't always representative of how firm the seat will be or its durability. Foam and coil resiliency refers to a cushions ability to return to it's original shape and comfort as time progresses.