On drywall work a smooth finish is simply that, the drywall finishing work is sanded down and then left without any sort texture. A common misconception of smooth is that it should be easier to do because there is no extra work completed to put a texture on the walls. However, a smooth finish entails just as much work, if not more, as a drywall texture. This is because a drywall finisher needs to spend the extra time going over their work and fixing any imperfections, which would otherwise have been hidden by a drywall texture. The process of obtaining a smooth finish is done by running a light over all of the finished areas to look for anyting that would stand out, when primer/paint is applied to the completed area, and then touching up that area and sanding it down again. The process of touching up and sanding down is done until the drywall finisher is satisfied that different light and shadows will not let any glaring imperfections stand out from the rest of the drywall work.