At some point or another you may find the need to neatly or cleanly separate an element of an image from its background. In this case I want to isolate a rose from an image while maintaining the integrity of the natural outline of the flower. This process is known as masking. Photoshop has been primarily considered a “Raster Based Image Editing Program” and for the most part, rightly so. Though in more recent incarnations of the program, the implementation of vector tools has drastically extended the potential to easily create amazing artwork. Although the eraser tool works very well for erasing the color information from pixels, it is often hard to accurately remove only the pixels surrounding the object you wish to isolate while preserving a clean profile. Aside from being inaccurate, the “eraser” method can be destructive to the image being edited, leading to one of those “OH NO!” moments we all have had (or will have) when the realization overwriting a file sinks in. I could bend your ear (or eyes in this case) for hours on practicing good file management, but this is a design tutorial so lets get to that.

1. First I will start with an image I shot on Valentines day in my back yard. Download the rose image here!



2. Using the “Pen Tool” my goal is to follow the outline of the rose as closely as possible, leaving the background just outside my path. The first step is to set my initial “Anchor Point”. Usually I find a corner somewhere in the image to start/end any path I create. (This is not necessary you can start your anchor points in the middle of a line or curve if you wish. Use what you find works best for you).

       


3. This next step will need to be repeated as necessary to achieve a level of detail satisfactory to your project. It may take a bit of trial and error to get used to the pen tool but every minute spent learning to use it will save you hours and headaches in the future. I use a few of Adobe’s predefined modifier keys (Ctrl, Alt, Option or Shift) to change how the pen tool interacts with my document. In this example the horizontal arrow shows where I placed my second anchor point, the diagonal arrow shows the direction I dragged the pen tool while continuing to hold the left mouse button after creating the second anchor point.



4. You will notice that two lines with circles on the ends will appear after making each subsequent anchor point, these are called “handles” and just as the handles on a bicycle allow you to steer, these handles give you precise control over the curves you create. If you are slightly off with one of your clicks don’t worry, you can easily fix the curve by using these handles. With the pen tool still active hold “Ctrl” and drag the handle between your last two anchor points, notice how the radius changes.

   At some point you will need to create an angle instead of a curve. This can be achieved easily by holding the “Alt” key (”Option” on Mac) and clicking directly on your last anchor point. This function resets the angle of the “open end” of your path, allowing you make hard angles as needed. Using the modifier keys to help you, finish tracing the outline of your image until you reach the point where you started. Now you should have one continuous path outlining the image as represented by the dashed black and white line around the rose in my example below



5. Now open the “Paths” window (Window > Paths) and right click on the icon of your outline and select “Make Selection…”

       


6. Open the “Layers” window (Window > Layers) and click on the “Add Layer Mask” icon in the bottom of the Layers window.



7. Your “Layers” window should now look like this:



8. …and your project file should now look like this:

I hope you enjoy using masks in Adobe Photoshop CS4 as much as I enjoy teaching you.