How to Do Ink Blots in Illustratorby Elizabeth Mott ; Updated September 28, 2017
If you've ever tried to draw an ink blot, you've realized it's easier to find a bottle of ink and drip a few drops than to create a believable freehand splotch using either traditional or digital drawing tools. Adobe Illustrator's live effects can help you turn some of the basic, symmetrical building blocks of vector artwork into a set of designs that look as if they fell from the nib of a leaky fountain pen.
Create three simple geometric shape: an ellipse, a rectangle and a rounded rectangle. Adobe Illustrator offers tools of the same names, nested together in the program's toolbox, that produce these design basics with one click on the artboard. Enter dimensions in each tool's dialog box to set the starting size for your inkblots-to-be. Space your clicks, and thus your graphics, far enough apart to leave room for their transformation.
Double-click on the "Fill" swatch in the Adobe Illustrator toolbox to bring up the Color Picker. Enter zero in the "B" field of its HSB color model sector to create a color with zero brightness. Regardless of the rest of your Color Picker settings, zero brightness defines black.
Click on the "Stroke" swatch in the Adobe Illustrator toolbox to bring it forward, then click on the "None" swatch to remove any stroke color, and thus any stroke weight, from your geometric shapes. "None" defines the absence of color, not the presence of white or a lack of opacity.
Switch to the Selection tool and marquee around all your geometric shapes. Open the Object menu and choose "Add Anchor Points." Adobe Illustrator adds new anchor points exactly midway between the control points that define your three starting shapes.
Open the Effect menu, click on its "Distort & Transform" submenu and choose "Roughen." Enter "10" in the size percentage field and "20" in the details per inch field as starting points for your transformation. Click on the "Preview" check box to evaluate your effect and increase or decrease its parameters as desired. Set the "Points" radio buttons to "Smooth," restricting Illustrator to creating curved distortions rather than jagged projections. Click on the "OK" button to add your effect.
Open the Effect menu again, go back to its "Distort & Transform" submenu and choose "Zigzag." Enter "3" in its size percentage field and "1" in its ridges per segment field to restrict the effect to adding small amounts of detail. Set the "Points" radio buttons to "Smooth" to avoid harsh, jagged edges. Click on the "OK" button to add the Zigzag effect on top of the Roughen effect.
Adobe Illustrator's Distort & Transform effects can produce extreme results as their parameters increase. Always preview your results to avoid having to undo unpleasant surprises.