The acid free paper may be the best option but there are some bags or 'socks' made from soft cloth that can be purchased at various sites.
My wife, being the dutiful little helper that she is

, makes mine. Actually, I do the cutting and such and she does the sewing. Almost any CLEAN cotton material will do. I have used everything from old Tee Shirt material (which is too thin) to some of the kids old pajamas. The felt like materials suit me the best and I have even bought some at a cloth store just for that purpose. With each knife tucked away in the little 'sock', I put them in wooden cigar boxes for storage in the safe, or where ever.
