Seen under a microscope the strands of fleece are scaly, just as is our hair. The felting process is about opening the scales with warmth and then closing them sharply with cold which makes them clinch on each other. To form a permanent bond it also involves a good amount of rubbing; it is quite a long process. The strands of fleece are disposed very carefully in layers crisscrossing each other so they can grab on each other and become inseparable and you cannot tear them apart any more.

There is no binder nor anything but the fleece involved in making the panels, except for a last rinse with some vinegar to ensure insects will be repelled and that the panels will conserve well.