Use the Bezier vector tools of image manipulation programs like Inkscape, GIMP and Adobe Illustrator to create a curved underline effect. Vectors are graphics you can enlarge to any size without loss of quality. One challenge in using vectors for underlines is that vector lines usually have a uniform width. To vary width, consider using additional vectors in those portions of the main underline vector that you want to widen.
Insert Text
- The curved underline effect requires text under which to appear. Run your program's Text tool to produce the text. If you're using Inkscape, the Text tool is represented by an "A" icon on the toolbar. GIMP also uses an "A" for text, and Illustrator uses "T." Click the canvas location at which you'd like to insert the text, and then type the text you want to underline with a curve. You can exit the text entry mode by clicking another icon on the toolbar.
Bezier
- After you've created some text to underline, you're ready to insert the underline itself. Use your program's Bezier tool for this task because Bezier curves are inherently smooth, in contrast to hand-drawn lines made with the Paintbrush and Pencil tools. Bezier curves are math constructs and have sets of control points. Two is the minimum number of control points for a Bezier curve and are all you need for a simple curved underline. By moving a Bezier curve's control points, you can shape the curve.
Insert Control Points
- To begin making the shape of the underline with a Bezier curve, click your program's Bezier tool. GIMP and Illustrator represent Bezier with a pen icon on the toolbar. Inkscape's Bezier icon is a blue cylinder joined with wavy lines. Next, plot the underline's first point directly under the left edge of the text you want to underline. Click your mouse on plot the point, and then drag to the text's right edge and click to plot the ending point of the underline.
Shape Curve
- The initial underline you make with two Bezier control points is strictly horizontal. To curve this line to stylize it, move the Bezier curve's control points. In Inkscape, click the second highest icon in the toolbar that's shaped like a black arrow. Click on the center of the line connecting the curve's control points and drag downward. The line will change to a curve, which you can further shape by dragging the curve's control points. GIMP's shaping tool is part of its Bezier tool. Create the curve the same way as you would in Inkscape, by dragging on the line connecting the Bezier curve's control points. In Illustrator, click the Convert tool, whose toolbar icon displays a "V." Drag on a control point to create the curve for the underline.
