You can determine whether or not foam is high density by; - Press the foam with your finger. The high-density foam tends to recover slowly when pressed since it’s more resilient than low-density foam. - Comparing the weight to other types of foam. High-density foams are much heavier than low-density ones - Looking for a "high-density" label on the packaging or in descriptions online - Comparing the price. Of course, high-density foam is of higher quality than low density; hence, it’s priced relatively high. - You can also tell if it's high-density by looking at how tightly packed together its cells are - Finally, the high-density foam will be more durable and last longer than a lower-density type