I used this product on a stainless exhaust. I scratched up the surface with some wet and dry sandpaper. and applied this product with a brush. After the exhaust went beautifully dark dark grey but could really see the brush marks. Afterwards I used a clean rag and reapplied the blackener in a consistent direction and it matted out all the marks and came up beautiful. very happy with the product. Will definitely recommend this product to anyone after blackening any form of stainless steel.