Through 18 months of research, Casper researchers learned that the average person sleeps with a combination of pillows, one firm and one soft, to achieve ideal comfort and support. Casper set out to design one single pillow that would adapt to changing positions and achieve the unique qualities that two very different pillows provide. After testing hundreds of pillows, Casper built custom prototypes in every material imaginable. The Casper pillow features dual layers: an inner core with shorter fibers to provide springiness in any position, and an outer layer with longer fibers for a cushy, luxurious feeling that is forgiving at any angle. Together, the outer layer and the inner core contain nearly one billion fibers. The minuscule fibers give the cozy feeling found in down, but the supportive qualities associated with foam — making the Casper pillow the perfect combination of the two.