One method that has been successfully used to hide streaks is, after the glass has been lightly sanded, cover the streak with a sharpie of the same background color, this may take more than one color sharpie to achieve the color desired (brown and red, green, black) many different colored sharpies out there. When it dries, use an alcohol saturated q-tip to clean the sharpie off. This may require more than one application. The alcohol tends to stain the glass using the sharpie as a dye. It's not perfect, but better than looking at the streak. Gordon's did have a good period for almost 20 months with little or no defect, but this spring it all came back to haunt us. The streaking I am told is due to lack of material or "dry" spots during the manufacturing process. When the fiberglass is fully saturated, there are no defects. Hope this helps, LF