Review on Swanson Tool T0118 Speedlite Square by Nathan Skipper

If only the edges were flat and smooth. I wish they sanded/smoothed the edges properly. There are still throw lines along all edges that affect the draw lines. Since they run right down the middle, they don't interfere with my ruler, which is thin enough to fit completely under this mold residue. Pretty square with the square test (draw a line, then flip the square and redraw). Slight deviation (<1/64) about 18 inches. Less than the width of my 0.5mm pencil lead. As I draw the lines, I feel my pen go into the grooves.