Zibra - Square Paint Brush for narrow surfaces The square brush was made with windows in mind! The narrow 1" brush head was shaped to fit in most window mullions perfectly, great when precision control is needed. The square brush also is a great choice when painting flat ledges, like on the arm of a chair. Narrow Molding Flat Edges Painting narrow surfaces like windows and window grids is now a pleasure when using the square brush. This brush is a favorite among many due to its perfect width and incredible bristle pack-out providing a smooth finish and fewer dips! Zibra - Square Paint Brush