How to Make Spirals in GIMP
Spiral images may elicit memories of childhood pinwheels and colorful kaleidoscopic images. Painting spirals from scratch requires a steady hand and the ability to draw perfect circles. GIMP, a free image-editing program, enables computer users to produce perfect spirals without ever touching a digital paintbrush. Simply activate GIMP's "IWarp" filter, adjust a few controls and click your way to perfect spirals in minutes.
Launch GIMP, and Press "Ctrl" and "N" simultaneously to open the "Create a New Image" window. Type 500 in the "Width" text box and 500 in the "Height" text box. Click "OK" to close the window. The main canvas appears in a new window. Its canvas size is 500 x 500 pixels.
Find the color box located near the center of GIMP's toolbox. The color box displays two overlapping rectangles. Click the top rectangle, and then click one of the colors that you see inside the "Change Foreground Color" window that opens. Click "OK" to close that window.
Return to the toolbox. Click the "Bucket Fill" tool, and then click the canvas. GIMP fills the canvas with your selected color. Go back to the toolbox and click the top rectangle in the color box again to open the "Change Foreground Color" window. Click another color in that window, and then click "OK" to close the window and return to the canvas.
Click the "Rectangle" tool located in the toolbox, and then draw a rectangle at the bottom of the canvas. Draw the rectangle so that it divides the canvas evenly in half vertically. Click the "Bucket Fill" tool, and then click anywhere inside the rectangle you drew on the canvas. GIMP fills the rectangle with that color. The canvas now consists of two rectangles. The rectangle on top is the first color you selected. The rectangle on the bottom is the second color.
Click "Filters" to open a drop-down menu. Click "Distorts," and then click "IWarp" to open the IWarp window. A small preview of your image appears on the left side of the window. Slider controls appear on the right.
Click the "Deform Radius" slider, hold down your left mouse button and drag the slider so that the value in the box next to the slider reads "150." Drag the "Deform Amount" slider until its value reads "0.20."
Click "Swirl CCW" to select that option, and then click "Bilinear" to check that option if it is not checked. Click the center of the preview image on the left side of the window. The image will warp by a small amount. Continue clicking the same point. As you do, a spiral begins to form. Its arms consist of the two colors you selected for the image.
Click "OK" when you are satisfied with the spiral. The "IWarp" window closes and applies your changes to the real image on the canvas.
Tips & Warnings
- The "Deform Amount" setting controls the size of the arms in the spiral. That setting is 0.20 in this example. Increase the value to create larger spiral arms. You can also experiment with the "Deform Radius" setting. Changing its value changes the spiral's shape. By choosing different colors and experimenting with the two slider controls, you can create a wide variety of unique spiral patterns.
- To change the size of your spiral, click "Image," and then click "Scale Image" to open the "Scale Image" window. "Width" and "Height" text boxes appear in the window. Click the drop-down on the right side of those text boxes and click "Percent." Type a number such as 50 in the "Width" text box and press "Enter." GIMP applies the same value to the "Height" text box. Click "Scale" to scale the image to 50 percent. Typing different values in the "Width" text box scales the spiral by the amount entered.
- Click "Swirl CW" to make a spiral with a clockwise swirl.