We will learn how to select the background using the Pen Tool rather than the Magic Wand in PhotoShop. For most people, the time saved using the Magic Wand to select the background far out-weighs the disadvantage of its accuracy. If you do need a lot more accuracy in your selection, you might want to learn how to use the Pen Tool. Of course there are so many more reasons to learn this tool, but today we will focus on using it to crop out a background. I have a sticker where I want to take just the wing on the left and crop out the rest of it.
Step 1: Selecting With the Magic Wand
First I will show you how the accuracy of the Magic Wand is lacking. I tool the Magic Wand, selected "Anti-alias" and "Contiguous" and set the "Tolerance" to 16, then clicked the background. All of the off-white area is now selected.
Step 2: Crop Out the Background
Once the background area was selected, I deleted that area. I used red to emphasize the inaccuracy the Magic Wand gives us. Like I said, to some people this is not that big a deal and since it only took a few seconds, this is good enough. (In fact, for what I need to use this wing for, this is way better than good enough, but, I thought I would show you how to use the pen tool, and I had to crop it anyway.)
Step 3: Use the Pen Tool Instead
If you do need a more accurate edge to your selection, you will be better off using the Pen Tool. Press "P" or select the Pen Tool off the tool box. There are a number of other "Pens" under the actual Pen Tool, but for the most part you can do these with just the pen tool by knowing where to select the anchor points.
Step 4: Start Drawing a "Path"
The line you are creating with the Pen Tool is called a "Path". You manipulate the path by laying down anchor points and adjusting the "Handles". You will "Click and Drag" to set the anchor then adjust the vector from each anchor. After you get the anchor set and a partial vector going, you can hold <Ctrl> the adjust the vector by selecting the handles on each point. I like to find a point in the picture where the arc I am following is bisected vertically or horizontally by the computer's pixel rows and place an anchor there. This way I can hold <Shift> while adjusting the handle without effecting the previous vector. Some times you can't always do this, and so you have to place an anchor in a location that can not be constrained at a 90 or 45 degree angle. This is fine, it just takes a little more work.
Remember, the less numbers of anchor points you have, the more smooth the Path will look, BUT, don't sacrifice the accuracy of the path to save anchors, that is the whole point of using the pen tool in the first place! Anther trick I use all the time is to place the anchors on the curve and loosely lay down the vector handles. Then, go back and adjust the path by holding the <Ctrl> (changes the Pen to the White Arrow) and pulling the path back into the shape of the curve I am tracing. For the most part this is kind of intuitive, but there is a sweet spot that will allow you to pull the path in 2 directions at once, like a "S" shape. This is kind of weird at first, but good to know.
Another trick I like to use is to place an anchor just before I go into a really tight curve. This allows me to get a really tight vector without needing to use 2 anchors.
Step 5: Here Is Your Path
When you are done you will have something like this. You will see the path and the anchors that belong to it. Obviously, the more you practice the better you will get, and the faster you will become. There are a bunch of little tricks you will learn while practicing, I am just going over some quick basics.
Step 6: Pen Tool Options
With the path set, you have a number of options you can use with the
path. You can fill it, "Stroke" it with the brush (if the brush is
selected, it will use the brush's settings"), set a selection, etc. One of the more confusing options is the "Combine" section. This allows you to combine a number of Paths into one object and decide how they will interact with each other. My suggestion is to just play with the various options and see which one you need. You can actually select more than one at a time if that is what you need. Usually if I can't get what I want after a few tries, I will cut and paste the paths into different layers and just manipulate them separately rather than sitting there wasting time trying to guess what I need to set.
Step 7: Better Accuracy With the Pen Tool
Once you learn the Pen Tool and its pros and cons as well as those of
the Magic Wand, you will be able to better decide which tool you should
use for the job. The Pen Tool can give you a more professional look when
it is needed and you can afford the time.