OK, now back on the hunt with the flashlight. I will tell you this is an extremely important stage and will take your work to the next level (glass smooth finishes). The initial grain filling with the spakling will get about 90 percent of them. The first round of glazing putty will get another 4 percent, but that 1 percent left is the difference between an average and a "show car" finish. Be ultra picky and look over the surface multiple times from different directions. This step is actually very fast and can be done in just a few minutes, so DON'T skip it.