I've been doing wool applique for a while now...and was told that for the wool to felt (puff up so it won't ravel much) it should be at least 70% pure wool. Of course 100% is best. Wash it in hot water and dry on a regular setting. Of course you may have to iron it. but do so before adding it to freezer paper to cut out. Stitching can be done with DMC embroidery thread ...2 strands. Enjoy...it's so relaxing!!