The most effective, comfortable and versatile pillows have loose fill. Many wool pillows available today are made from carded wool. These are fine for moisture control and are often initially comfortable. However carded wool (long fibres laid out flat) compress with use and felt with washing. Wool batt pillows cannot be shaped and adjusted to accomodate different sleeping positions or various levels of mattress firmness. SnugSleep wool knops are very resilient,can easily beshaped to maintain correct neck and spinal alignment,and are easy care.