2 - Select the “Ellipse Tool” (L) and create a small “Circle” (it should be about 3 px in diameter). To do so, hold the “Shift” key while dragging down and right. Fill it with Black and “No Stroke”. “Lock” it in place by clicking the small Padlock on the left side of its Thumbnail in the “Layers Panel”.
3 - Select the “Blob Brush Tool” (Shift + B), double-click on top of it in the “Toolbox” and change the “Size” to 1 pt.
4 - Create a “New Layer” by clicking the small button at the bottom of the “Layers Panel” and use the “Blob Brush” to draw some circular shapes of different sizes radiating from the original circle.
5 - Right-click on top of them, choose “Group”, then “Copy” (Command/Control + C) and “Paste” them (Command/Control + V). Place the copy overlapping the original a bit to create a better pattern.
6 - Repeat as many times you want. Don’t forget to “Group” them together once in a while (Command/Control + G). You can also “Rotate” the duplicate/s to achieve a better pattern.
7 - Unlock the “Circle” Layer, select everything and duplicate it. Copy” (Command/Control + C) and “Paste” it (Command/Control + V) and repeat as many times you want to make it denser.
8 - Create several “Clusters” with more or less Blobs to achieve different “Stipple” densities.
9 - Once you are done, select one of the “Clusters” and in the “Brushes Panel” click on the “Top-Right” Menu and choose “New Brush”. Make it a “Scatter Brush” and use the following values: (Size: Random from 5% to 200%, Spacing: Fixed 10%, Scatter: Fixed 0%, Rotation: Random 150%, Method: Tints). Don’t forget to name it. Repeat with the rest of the “Clusters” to create more Brushes.
10 - Test them using the “Brush Tool” (B). You can resize them a bit changing the “Stroke Weight”. You can delete the “Clusters” if you want but remember to “Save” your brushes.
11 - Open the “Vector” Image you want to work it and use “Swap Fill and Stroke” (Shift + X) if needed.
12 - Copy” (Command/Control + C) and “Paste” the image in your original file (Command/Control + V). You may need to resize or change some of your brushes settings. To do so, double-click its thumbnail to open the “Options” window (we reduced the “Maximum Size” value to 50%). Apply the brush to the portions of the image you want to shade using the “Brush Tool” (B) or the “Pen Tool” (P).
13 - You may Mask some of it by creating a White filled rectangle covering the “Image”. Right-click on top and choose Arrange > Send to Back.
14 - Select the portion of the vector you want to use and the white rectangle together (“Shift” key), head to the “Pathfinder Panel” and choose “Minus Front” to create a hole in the white rectangle with the desired shape. Position the Stipple shading you created under the white rectangle with the portions you want to use showing because of the hole.
15 - You can also use the brushes around some of the shapes and then Swap the “Fill” and “Stroke” color of the image (Shift + X).