How to Fill a Background With Polka Dots in Illustrator

By Elizabeth Mott

To create a polka dot-patterned fill that covers the background behind text or graphics in an Adobe Illustrator document, you could draw your pattern dot by dot -- or simplify your task by creating an Illustrator pattern swatch and applying it to a background object. Adobe Illustrator's patterns make quick work of filling large areas with repeating geometric shapes or irregular textures. The trick to crafting just the right pattern swatch lies in the precise use of dimensions and boundaries.

Step 1

Decide how large or small to make your polka dots. Select the Ellipse tool from the Adobe Illustrator toolbox and draw a few test circles. To constrain the Ellipse tool's operation to drawing true circles, hold down the "Shift" key while you drag to create your shape.

Step 2

Choose the angle at which your pattern will repeat. Most polka dot patterns follow either a straight horizontal or a diagonal axis.

Step 3

Choose colors for your polka dot pattern. You may prefer an all-over fill made up entirely of circles of the same color. You also can create a pattern with a repeating set of circles of different colors. Select your choices from a color library or create them yourself. To choose from a color library, open the Swatches panel by choosing "Swatches" from the Window menu, then open the panel's fly-out menu at its top-right corner. Choose a library from the Color Books fly-out menu of the Open Swatch Library fly-out menu. To create a color mixture from scratch, open the Color panel by choosing "Color" from the Window menu. Move the color sliders till you see the color you want, then drag the display swatch from the Color panel to the Swatches panel.

Step 4

Create the minimum number of circles to build a repeating pattern along your chosen axis and with the color range you selected. To make sure you space your repeated circles an equal distance apart, open the Transform panel by choosing "Transform" from the Window menu. Choose the Selection tool from the Adobe Illustrator toolbox and select one circle. Note the width and height of your circle, which should be identical. Click after the current value in the measurements field marked "X," type a plus sign and the dimension of your circle, then hold down the "Alt" key (Windows) or "Option" key (Mac) while you press "Return" to create a duplicate circle at the new location. Continue creating duplicates until you have enough for your pattern.

Step 5

Choose the Selection tool from the Adobe Illustrator toolbox and select all the circles you want to be the same color. If you plan to make your pattern only one color, you can marquee around all your circles with the Selection tool. If you need to select only specific circles, click on the first one, then hold down the "Shift" key while you select the others.

Step 6

Click on the appropriate swatch in the Swatches panel to apply its color to the circles you selected. Click on a blank area of your artboard to deselect those circles, then select another set to color as necessary until you have applied color to all your polka dots.

Step 7

Select the Rectangle tool from the Adobe Illustrator toolbox. Draw a box from the center of your top-left circle to the center of your bottom-right circle. Set the fill of this box to None by clicking on the "Fill" swatch in the toolbox, then on the icon at the bottom right of the toolbox that consists of a box with a diagonal red line through it. Click on the "Stroke" swatch in the toolbox, then on the "None" swatch in the toolbox.

Step 8

Place your new bounding box behind your polka dots by choosing "Send to Back" from the Arrange fly-out menu of the Object menu. Choose the Selection tool from the Adobe Illustrator toolbox and marquee around your circles and bounding box to select all the elements you need for your pattern.

Step 9

Choose "Define Pattern" from the Edit menu and enter a name for your polka dots in the "Swatch Name" field. Click on the "OK" button to create your pattern. Apply your new pattern by creating an object to serve as the background behind your main graphics or text, then clicking on your polka dot pattern in the Swatches panel.