Buy memory foam by the actual weight. That's right! Just like meat or produce, the only way to tell if you are getting what you paid for is to actually weigh it! There is no mystery to it. A King Size, 4" topper at a 5lb density will weigh 70lbs. If it doesn't, then either they cut the foam short of your bed size, or you got a lower quality foam.
We encourage our customers to actually weigh their foam when they receive it, and double-check that number with the delivery weight, or the chart on our website.
What's the big deal, anyway? The heavier the foam is, the longer it will maintain it's shape without sagging or losing it's restorative properties. So it's critical that if you paid for 5lb foam you get it. Accept no substitutes.
Buy U.S. memory foam. In our experience, many offshore and imported memory foam products contain fillers and additives to get the weight up, but without the true, long-lasting properties of memory foam. At the end of the day, you're looking for performance...don't accept an imitation or knock-off product.