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By Lauren Harmon |

Deke's Techniques: Making a danger sign more dangerous

Take a warning sign to the next threat level with Adobe Photoshop. In this week’s Deke’s Techniques, Deke McClelland takes a photograph of a real-life sign from The Cliffs of Moher in Ireland—better known as The Cliffs of Insanity in the movie Princess Bride—and adds a menacing shark with the combined power of paths, channels, clipping masks, and some other tools in Photoshop.


  1. Open the image in Photoshop, go to the Paths panel, and select the shark body path. This is a simple path outline with four anchor points.
  2. To convert the path to a shape layer, go to the Layers panel, press the Alt (Windows) or Option (Mac) key, and click the black/white circle icon at the bottom of the panel. Choose Solid Color from the popup menu.

Pro tip: Holding down the Alt or Option key adds the adjustment as a new layer. Name the new layer Shark and click OK.

  1. Turn off the visibility of the Shark layer and select the developed photo layer. Select the Lasso tool, press and hold the Alt or Option key, and click around the cliff in the sign, leaving a wide white margin, as shown in the image below.


  1. Copy your selection to a new layer by pressing Ctrl+Alt+J (Windows) or Command+Option+J (Mac). Name the new layer cliff.
  2. Choose Edit > Transform > Flip Horizontal to flip the cliff to the right side of the composition. Then choose Edit > Free Transform to scale the cliff layer. Choose bottom right reference point from the matrix in the Options bar that appears are the top of your window and change these values to the following:

W or Width to 124X to 3342Y to 2702

  1. Switch to the Channels panel. Drag the Red channel to the page icon at the bottom of the panel to create a copy of it. Rename the new channel mask and then press Ctrl+I (Windows) or Cmd+I (Mac) to invert the mask channel.
  2. Increase the contrast in the channel by choosing Image > Adjustments > Levels. Change the Input Levels in the Levels dialog box to 100, 1.00, and 200 and click OK.


  1. Now we’re going to clean this mask up a little bit. Press B to switch to the Brush tool and D to load the default foreground and background colors. Right-click in the image window and increase the Hardness value in the popup menu to 100%.

Now zoom way in on your cliff and click on any of the black specks you see to paint them away. You can change the size of your brush with the right and left bracket keys.

  1. Now switch back to the Lasso tool, press and hold the Alt or Option key, and select all the way around the cliff, leaving a black margin around it, similar to your selection in Step 3. Now choose Select > Inverse and then press Ctrl+Backspace or Command+Delete on the Mac to fill everything outside of the selection boundary with black.
  2. Deselect the image and Ctrl-click (Windows) or Cmd-click (Mac) on the mask channel thumbnail to load the channel as a selection.

  3. Click the RGB channel and return to the Layers panel. Turn off the cliff layer and turn on shark. Select the shark layer and click the Add LayerMask icon at the bottom of the panel to convert your selection outline to a layer mask.


  1. Back to the Paths panel! Copy the mouth path and paste it in the Shark Shape path. Go to the Path Operations icon in the Options bar and choose Subtract From Shape.
  2. Select the sweat path, marquee-select the path outlines, and copy and paste them into the Shark Shape path.

  3. To add the sweat path to the layer mask, switch to the Layers panel and click the layer mask thumbnail attached to the shark layer. Choose the Marquee tool and marquee-select the general area they appeared in. Press Alt+Backspace or Option+Delete on the Mac to fill the selection with white.

  4. Deselect the image, return to the Paths panel, and press A to switch back to the Selection tool. Select the teeth path, select the path outlines for both the top and bottom rows of teeth, and copy and paste them into the Shark Shape path.

Check out the details in the video for instructions on sharpening, lengthening, and rotating the shark’s teeth to make it even more ferocious.


  1. Finally, switch back to the Layers panel. Drag the cliff layer above the shark layer, turn it on, and press the Alt or Option key while clicking on the horizontal line separating the cliff and shark layers to combine them in a clipping mask.


Now visitors to the Cliffs of Insanity have been properly warned. If you’re a member of lynda.com, Deke has a follow-up movie in which he shows you how to enhance the credibility of this shark. If you’re waiting for next week’s free technique, you can look forward to precisely aligning elements to a bleed inside of Illustrator, creating an interesting piece of vector artwork along the way.

Check back for more Deke’s Techniques each and every week from Deke McClelland and lynda.com.

Interested in more?

• Start your 7-day free trial to lynda.com today • The entire Deke’s Techniques collection • Photoshop CS6 One-on-One: Intermediate

Adobe and Photoshop are registered trademarks of Adobe Systems Incorporated.

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