This trombone cozy was necessitated by a skin allergy to certain metals. It is a rectangle of soft cotton material with velcro sewn on so that it wraps snugly around the portion of the horn that comes in contact with the trombonist’s neck. I measured the length of the tube we wanted to cover, and wrapped a string around it to get the circumference. I added a bit seam allowance and overlap for the velcro to start with a rectangle of material about 3″ x 7″ and a 6.5″ strip of velcro. I rolled a hem around the four sides and sewed the velcro on. Problem solved– no more neck irritation makes for a much happier band member.