Here’s a cool effect you can achieve quickly in Photoshop: turning a photograph into a sketch. This gives a nice “arty” effect, and if you wish you can then continue to work with the image by adding color or drawing in new elements of your own.
The first step is to choose an appropriate photo. You can try this with just about any photo, but a photo with good contrast and without too much detail in the background is a good place to start.
Step 1 – Save the file with a new name
Always keep your original photo safe, you don’t want to lose it by saving over it with your sketch version. Open the photo in Photoshop and then save it with a new name: perhaps use the same name but add the word “sketch” to it. Now your original is safe, so you can work with this and still have the original photo file.
Step 2 – Desaturate The Photo
Choose Image> Adjustments> Desaturate. This gives us a grayscale version of the photo. You can also use Image> Adjustments> Black and White on newer versions of Photoshop.
Step 3 – Duplicate the Layer
Duplicate the layer your photo is on. For a photo, you’ll only have one layer to start with, probably called “Background”. The name isn’t that important, though. Select this layer drag it over the New Layer icon. Now you have 2 layers, the original layer and one with the word “copy” in it..
Next we’ll be working with the new layer, probably named Background Copy.
Step 4 – Invert the New Layer
In the layers palette, select the new layer you just created. Then go to Image> Adjustments> Invert. This will turn this layer into a negative.
Step 5 – Change The Blend Mode
In the Layers Palette change the Layers Blend Mode for this layer to Color Dodge. It may look like your photo disappeared, or at least went mostly white. Don’t panic, that’s what should happen.
Step 6 – Apply The Gaussian Blur Filter
While on the new layer, use Filter> Blur> Gaussian Blur. Now move the Radius slider to the left. Then start sliding it to the right.
As you move the slider, you’ll see the sketch take form. Experiment until it looks like a proper sketch. Bigger numbers create a stronger effect, but if you go too far your image will start looking more like a photo than a sketch. If your image is looking too photographic, drag the slider back to the left.
Other Blur Techniques
You aren’t limited to Gaussian Blur, you can also get this effect with Motion Blur and Radial Blur. Depending on the photo, one of the other blur methods may give you a better result. Experiment for the best results.
Coloring Your Sketch
One way to paint over without losing your detail is to add a new layer on top of the sketch and set the Layers Blend Mode to Multipy.
Paint over. As long as your colors are not too dark, the texture of your original will stay in place. You can always go back to the sketch layer and play around with the blur settings after you color.