A binder is applied to particles which are then combined with fibers to bind the particles to the fibers. The particles have functional sites for forming a hydrogen bond or a coordinate covalent bond. The fibers have hydrogen bonding functional sites. The binder comprises binder molecules. The binder molecules have at least one functional group that is capable of forming a hydrogen bond or a coordinate covalent bond with the particles, and at least one functional group that is capable of forming a hydrogen bond with the fibers. Particularly suitable binders include glycerin, a glycerin monoester, a glycerin diester, a polyglycerin oligomer, propylene glycol, a polypropylene glycol oligomer, urea, and combinations thereof. A substantial portion of the particles that are adhered to the fibers may be adhered in particulate form by hydrogen bonds or coordinate covalent bonds to the binder, and the binder may in turn be adhered to the fibers by hydrogen bonds. Fibers containing particles bound by this method are easily densified.