I had old shellac on that had to be removed, so Olga just filed it away without applying any nail polish remover before. She has done it so vigorously, that my nails got thinned to the point when it was painful. Both of my big toe nails are still thin and red more than a month after the treatment, so I cannot apply gel to them until they grow back. Nail polish application afterwards was also messy. Overall, I would not recommend and would not go again myself.