4 x Liberon Steel Wool Grade 0000 Ultra Fine 7g. Steel Wool Grade 0000 is a flexible, ultra-fine steel wool used to cut back between coats of varnish, paint or oil finishes. It is ideal for polishing and cleaning delicate surfaces, including metals such as bronze, copper, chrome, stainless steel and aluminium, or with soapy water to clean and polish porcelain, marble and glass without marking.