Step 1: Pop Art Vector
To start out our pop art vector tutorial, we will start from a line drawing of the face in close up. This line drawing could have been with simple strokes, nothing too complicated.
Next, we'll create the shadows with objects filled with solid black. Use the Pen Tool (P) to draw the objects and try to give volume and movement to the illustration. Take a special look at how we drew the hair strokes and the shadow under the chin.
Choose the colors you'd like to use in your pop art vector illustrations. I chose the typical colors used in pop art illustrations to make a more obvious effect, but you can choose the colors that better represent your photo (if you made the drawing from a photo) or illustration.
Next, we'll create the swatches for the dots background of the objects.
We need the grid guideline to make the dots swatch for every color. Reveal the grid by going to View> Show Grid. Make sure you have “Snap to Grid” enable. Go to View> Snap Grid to check if it's enabled. If it has a check mark next to it, it's enabled. If it does not, click to enable.
Draw two circles with the Ellipse Tool (L). Hold the Shift key while drawing the ellipse to constrain the proportions and create the circle. The space between the circles would determine the predominant color in the swatch. The closer the circles are, the more predominant the circle's color would be the background color. Also, the more space the dots have, the more noticeable they would be to the human eye. In this tutorial, I'd like them to be pretty noticeable.
Now duplicate the two circles and rotate them 90 degrees using the Rotate Tool (R). Click and hold the Shift key to rotate in increments of 45 degrees. Next, draw a square with the Rectangle Tool (M) where each side goes through the circles' center point.
Duplicate four times each set of square + dots, one for each color that our illustration has. Now fill each set of circles with the colors of our illustration. Finally, fill the square with white. Now we are ready to create the swatches from this elements! Select the first square with the circles inside and go to Edit> Define Pattern. Name your swatch if you'd like, and click OK to create the swatch. Repeat the process for the other colors. You'll see the new swatches available in the Swatches Panel.
Replace the colors of the objects in our illustration with the new swatches. Select each object and click on the corresponding swatch in the Swatch Panel. Definitely starting to look like a pop art vector!
If you are unhappy with the way any of the swatches look as patterns in your illustration, you can play with the background color to create other tones.
Now we are going to take care of the strokes used to give expression to the face. This is single strokes with no fill. There are some for the nose profile, cheeks, forehead, etc. Open the brushes panel (Window> Brushes) and click on the top right icon to reveal its menu. Select Open Brush Library> Artistic> Artistic_Ink.
A new panel will appear. Now select one of the strokes and click on the bottom brush named “Tapered Stroke” in the panel we just opened. Do the same with the rest of the strokes. I applied the brush to all of my elements in the illustration to have the edges between them perfectly aligned.
If the brush for the expression lines is too wide or too thin (depends on the size of your illustration), you can adjust the brush width. Go to the brush panel where you'll find the brush you use for the expression lines. When you select a brush in any of the brush library panels, it's added automatically to the main Brush Panel. Double click on the brush and in the Width slider, move the arrow to the left to make the stroke thinner or to the right to make them wider. Click OK when you're finished.