Master Adobe Illustrator skills such as using clipping masks, the Blob Brush tool, the Eraser tool, and the Reflect tool with this detailed tutorial.
This exercise is excerpted from Noble Desktop’s past Adobe Illustrator training materials and is compatible with Illustrator updates through 2020. To learn current skills in Illustrator, check out our Illustrator Bootcamp and graphic design classes in NYC and live online.
Topics covered in this Illustrator tutorial:
Clipping masks (shapes), The Blob Brush tool, The Eraser tool, The Reflect tool
Exercise Preview
Exercise Overview
Prepare for takeoff with the Clipping Mask function! This exercise shows you how to fit complex patterns and artwork within equally complex shapes.
In the Illustrator Class folder, open the file Mask Till You Drop.ai.
Zoom out so you can see the objects to the right of the artboard.
Arranging Artwork to Be Masked
Choose the Selection tool
.Drag the path of the shield over the orange ray background.
Drag the airplane into place inside the shield outline. It should be centered slightly to the right and toward the top of the shield outline, as shown in the preview image at the beginning of the exercise.
Select the path of the shield, then go to Object > Arrange > Bring to Front.
Applying the Mask
Use the Selection tool
to select the shield, the plane, and the background. You can Shift–click each object, or you can drag a marquee from the top left of the document over all the objects to select them.Go to Object > Clipping Mask > Make.
Deselect everything by clicking off of the artwork to see the effect! Because the shield was the topmost object, it defined the border of the clipping mask.
The edge of the shield needs color, so let’s apply a stroke to the mask. With the Group Selection tool
, select the shield outline path.In the Properties panel to the right of Stroke, set the weight to 15 pt.
Color the Stroke with the Brown Shield Edge swatch. (Mouse over the swatches to see names.) Remember to press Return/Enter to close the Swatches panel.
Editing Shapes with the Blob Brush
The Blob Brush 
works a lot like the Brush tool, but it draws a complete shape instead of drawing a path with a stroke. It will also add to the area of an existing object of the same color. Let’s try it out!
With the Selection tool
, select the leaves artwork.In the Tools panel, choose the Blob Brush tool
. You may have to click and hold the Paintbrush tool 
.Double–click the Blob Brush
to bring up the brush options.-
Choose the following settings in the brush options dialog:
Size: 4 pt Angle: –48° Roundness: 80% Click OK.
Finish perfecting the artwork of the leaves by painting with the Blob Brush
to extend the stem so it is longer (feel free to refer to the example).-
You can also use the Blob Brush to edit the other leaves as you see fit. Use the Eraser tool
to correct any mistakes or to carve out parts of the leaves.Some Blob Brush Tips
A good habit to prevent unexpected behavior with the Blob Brush is to first use the Selection tool
to select the object you want to edit, then switch to the Blob Brush.Using the Blob Brush in Outline mode (View > Outline) can give you a better idea of how it automatically merges paths.
- While using the Blob Brush, holding Opt (Mac) or Alt (Windows) temporarily switches to the Smooth tool
, which is useful for smoothing out a rough shape without interrupting your flow.
Masking a Pattern
With the Selection tool
, select the leaves artwork again.Drag the leaves into place over the brown textured rectangle, making sure the leaves are completely inside the rectangle.
Shift–click the rectangle to select it as well.
With both objects selected, go to Object > Clipping Mask > Make.
Drag the leaves into place underneath the shield.
With the leaves still selected, go into Object > Transform > Reflect.
In the Transform dialog, make sure the Axis is set to Vertical.
Click Copy (do NOT click OK).
-
Drag the copy of the leaves into place on the other side of the shield.
TIP: Holding down Shift after you start to drag lets you constrain the movement to a straight line.
With the new set of leaves still selected, Shift–click the leaves on the left side of the shield to add them to your selection.
Go to Object > Arrange > Bring to Front. Now both sets of leaves should be in front of the shield artwork.
You’re finished! Save the file as yourname-Mask Till You Drop.ai.
In the dialog that appears, leave the default options checked and click OK.
