Which tool is used to draw a line? A scale or ruler is used to draw a straight line. What are the tools used in MS Paint? MS Painting Tools Functions. Select. The "Select" tools look like a star or rectangle outlined with hashed lines. Eraser. Under the star "Select" tool is the "Eraser" tool. Fill Tool. The "Fill Tool" looks like a jar that has paint spilling out of it. Pick Color. Magnifier. Text. Line and Curve. Polygon.