A sketch is a free hand drawing. In Adobe Learn Photoshop, you can add a sketch effect to any color image or photograph and give it an artistic feel, or perhaps trick your friends into thinking you've suddenly become an amazing sketcher.
Step 1

Open a color image in Photoshop. To get the best sketch image, high contrast images are preferable. If it's needed, you can adjust the image's contrast (Image>Adjust>Brightness/Contrast).
- Optional: After you choose an image (but before you adjust the contrast) select that image by pressing (Ctrl + A) and then press (Ctrl + C) to copy that image. Open a new Photoshop window and paste that image in the new window by pressing (Ctrl + V). Save it as a copy. This is done to preserve the original image.
Step 2

Desaturate the layer that contains the image. You can desaturate by clicking on Image>Adjust>Desaturate.
Step 3

Duplicate the desaturated layer. On the layer palette, you can duplicate the layer by right clicking on the previous layer and selecting the option of duplicating that layer.
Step 4

Note that there should now be at least two layers: two desaturated layers, and depending on which version of Photoshop you're using, you may have a blank background layer.
Step 5
Select and invert the duplicate desaturated layer. You can invert an image by clicking on Image>Adjust>Invert.
Step 6

Notice that now, with the inverted layer selected, change the blending mode to "color dodge." The image will turn all white with few black spots on it.
Step 7

Set the Gaussian blur to this layer. You can do that by clicking on Filter>Blur>Gaussian Blur. Then you can set the radius in between 4.0-9.0. Choose the one that creates a nice sketch effect.