4inches of compacted memory foam makes a firmer than firm pillow. A thermafoam salesman told my friend to stomp on the pillows for a minute a day until they soften up. Tried this didn't work. May have to use them as seat cushions for awhile to break down their firmness. Also queen size pillow cases do not fit them well. four inches is not deep enough for typical pillow cases.Still a good buy for the product.