This is the second most holy and pure acid-stained floor in the history of the universe. It is an English Red acid-stained concrete overlay of a finished basement floor. Concrete overlays provide a clean canvas for old concrete that optimizes the antiqued look of acid stain. The first photo shows the floor after removing black cutback tile adhesive by concrete diamond grinding. The second photo shows this concrete overlay immediately after applying the acid stain. The last two photos show the floor color after the chemical reaction was complete and this overlay was sealed with a solvent-based acrylic lacquer.