Way back in Hour 3, “Making Selections,” you learned how to make selections that can isolate the part of the image so that you can work on it without affecting the rest of the image. Then in the last hour, you learned how to convert selections to masks to hide the parts of your image that you don’t want to show and to preserve selections so you can recall them later. The problem with selections is that it can be difficult to achieve a precise shape. Photoshop has all kinds of tools for creating selections based on the image content, by following object edges or choosing similarly colored areas, but what if you need to select a very smoothly curved area? Or a triangular area?
Paths offer you a way out of this dilemma. Using paths, you can create and save selections for future use, the same way you can save a mask to preserve a selection. Paths are saved right within the Photoshop file, along with layers, layer masks, channels, and all the rest. And because paths are vector based instead of pixel based, you aren’t restricted to the shapes you can create with the Selection tools. You can draw very precise shapes and smooth curves with the Path tools. Then you can use these shapes as the basis for selections, stroke and fill them as objects or lines in your picture, or turn them into vector masks.
Let’s start by exploring the different ways to create paths. Then we’ll look at techniques for editing and using them in Photoshop.
You can create paths in three different ways (or you can use a combination of these methods):
Create a path from scratch by using the Path tools to draw the path by hand.
Create a path using the Shape tools, which you learned about in Hour 7, “Drawing and Combining Shapes.”
Making a selection and converting it to a path is often the most efficient way to create a path. Let’s look at an example. Figure 13.1 shows the test image, a tire gauge. I’ll select the object and make what’s called a clipping path to clip it out of the background. Without Photoshop, you could achieve the same effect with a photographic print and a pair of scissors.
As you remember, you can create selections using several different tools. For this image, I selected the background with the Quick Selection tool and then cleaned up the selection using Quick Mask mode. Other objects might be selected more easily by using a combination of the Elliptical Marquee and the Polygonal Lasso. You might even need to use several Selection tools in turn to achieve the selection you need. Just keep the Shift key pressed as you apply each new tool, to merge the selections into one. Figure 13.2 shows my final selection.
Convert a Selection to a Path
Starting with a selection of your own, follow these steps to convert it to a path:
First, make sure that the Paths panel is visible. If you don’t see it, choose Window, Paths to bring it up.
Choose Make Work Path from the Paths panel’s pop-up menu (see Figure 13.3).
The only option that you can set in the Make Work Path dialog is Tolerance (see Figure 13.4). Tolerance, measured in pixels, refers to how closely Photoshop follows the outline of your selection in creating the path. The lower the Tolerance value, the more exactly the path conforms to the bounds of the original selection.
For this image, I first tried a Tolerance of 5 pixels. As Figure 13.5 shows, the results were nowhere near what I wanted. Photoshop’s approximation of the selection at this setting was way too loose; you can see in the figure that the path doesn’t follow the outline of the valve stem closely enough.
Figure 13.5. When the path doesn’t match the selection closely enough, the Tolerance is set too high.
Caution: It’s a Long and Winding Path
Be aware that complex paths with lots more points and angles can be resource intensive; images that contain them are larger, save and open more slowly, and take longer to print
When this happens, the answer is simple: Undo. Then try the path conversion again with a lower Tolerance value. After some experimentation, I found that a value of .5 pixel worked quite well for this picture (see Figure 13.6).
Once created, the path appears in the Paths panel (see Figure 13.7). Photoshop names it Work Path, but you can rename the path by double-clicking it in the Paths panel. In the Save Path dialog, type the new name and click OK, as shown in Figure 13.7.
Now that you’ve created the path and given it a name, all that remains is to choose Clipping Path from the Paths panel pop-up menu and specify the path you just created as the clipping path.
Although renaming the work path isn’t required, it’s a good idea to make this a habit, especially if you might need the path again. If you leave the path labeled as a work path and then start a second path, one of two things will happen. First, if the work path is still active in the Paths panel, the new path will be added to it as a subpath. Second, if the original work path is not active in the Paths panel, it will disappear and the new path will replace it. You can choose Undo or use the History panel to go back and recover the original path, but it’s easier to simply rename it at the time of creation, turning it into a regular path that only you can delete.
Sometimes making a selection is too difficult or requires too much work on a certain image, particularly if you want it to include smooth, complex curves. In that case, you can use the Path tools to draw the path by hand.
If you’ve used vector-based illustration programs, such as Adobe Illustrator, you’re already familiar with Bézier-based drawing tools such as Photoshop’s Path tools. If you haven’t used these kinds of tools, however, you should know that mastering them takes a little practice—but the payoff is well worth the effort. In addition to the standard tools that draw a straight or curved line and add or remove points on the line, Photoshop provides the Freeform Pen tool. This tool gives you the power to draw any kind of line you want—straight, curved, or squiggly—and turn it into a path. When used with the Magnetic option, the Freeform Pen tool makes drawing around a complicated object much easier.
Each end of a Bézier curve is defined by three points: one on the curve and two outside the curve at the ends of handles that you can use to change the angle and direction of the curve. If this sounds confusing, don’t worry; you’ll see some examples soon.
Use the Pen Tool
The best way to learn how to use the Pen tool is simply to play around with it in a new Photoshop document. Let’s take some time to do that now.
First, create a new Photoshop document that’s big enough to give you some working room. Photoshop’s default size (7×5 inches) should work fine, and a plain white background will enable you to see the Pen’s paths easily.
Switch to the Pen tool (its button in the toolbox looks like a fountain pen nib) and make sure that the Paths panel is visible.
In the Tool Options bar, click the Paths button—it’s the middle one in the first group of three at the left end of the Options bar.
Click somewhere near the left edge of the page to begin your path. (Notice that Photoshop immediately creates a path called work path in the Paths panel. You can rename this path later in the same way described in the previous “Try It Yourself.”)
To draw a straight line, move your cursor anywhere else on the canvas and click. (Don’t hold down the mouse button while you’re moving; we get to that technique in a bit.) You’ve just created a corner point, which means that Photoshop connects this point and the first one you drew with a straight line (see Figure 13.8).
To continue the path with a curved line, move your cursor to the bottom of the window and then click and drag left. You’ll see a curve immediately appear and change as you drag (see Figure 13.9). You’ve just created a smooth point, which means that Photoshop creates a smooth curve where two curved line segments meet. After you click to position the point, your dragging positions its handles, which control the angle and degree of its curve.
To make this clearer, add another smooth curve to your path. Move your cursor to a point above and to the right of the second point, then click and drag to the right and a bit down. Another smooth point and another curve are created (see Figure 13.10).
Stop and take a look at the point you created in step 5. It forms a nice smooth curve between the point you just created and the point you created in step 4. That’s what a smooth point is all about.
As you have no doubt noticed, each smooth point has two handles positioned 180° from the other. You can use these handles to change the angle and direction of a curve after you’ve established it. You’ll learn more about how to modify curves in the “Editing Paths” section, later in this hour.
Switch to another tool or click your starting point to end the path. Unlike selections, paths don’t need to be closed.
Okay, by now you should have the basic idea: You create straight lines via corner points and make curved lines using smooth points. But you have to know more about each kind of point to use it effectively.
Corner points are easy. No matter what kind of lines a corner point connects, the result is always an angle, not a curve. If a curved line ends in a corner point, the smooth point at the other end of the line controls the curve’s angle (see Figure 13.11), because corner points don’t have any handles that you can use for adjusting curves.
As you saw in this hour’s first Try It Yourself exercise, the behavior of smooth points is a bit more complicated than that of corner points and takes some getting used to. A smooth point always creates a smooth curve between two lines (see Figure 13.12), and its direction handles are always directly opposite each other.
You can call upon one last kind of point when you need it; Adobe calls it a corner point with independent direction handles, but it’s also often called a combination point. It’s what you get when you put a corner point between two curves.
Create a Sharp Curve
Curves with a combination point in the middle can look like a stick seagull. The following steps show you how to create one:
Set up a new Photoshop document and begin a path by clicking to set an initial point.
For the second point, create a smooth point as you normally would: by dragging after you click to set the point, making a curved path.
Now move the cursor so that it’s exactly over the smooth point you just created. Press Option (Mac) or Alt (Windows) as you click and drag the mouse in the direction of the intended “bump” in the new curve. Release the key and the mouse button. Your path should now look fairly close to what you see in Figure 13.13.
Move the cursor to the position where you want the line to end; then click and drag in the opposite direction than the way you dragged in step 3. The line will curve neatly from where you ended the first arch to where you just clicked at its endpoint. As you drag, the curve expands farther upward. Figure 13.14 shows the resulting path, containing two smooth points (at either end) and one combination point (in the middle). If your ‘curve doesn’t match this configuration, click on each point in turn and use the point’s handles to reshape the curve.
While you’re clicking and dragging to create all these points and lines, you might think that a preview feature would be very helpful. Fortunately, Photoshop provides one. Look at the Tool Options bar and locate the downward-pointing triangle at the right end of the strip of tool buttons. You’ll see an option called Rubber Band; click the check box to turn it on. Activating this feature enables you to preview both straight lines and curves before you click to create them. Experiment to see this feature at work; if you don’t like it after all, you can go right back to the same menu to turn it off again.
To complete a path, you have two choices: close the path by connecting the final point to the initial point, or leave the path open.
A closed path is a loop with no beginning or end. To close a path, follow these steps:
Use the Pen tool to draw a path, using whatever points you want.
After you’ve clicked to place the last point, move your cursor right on top of your initial point. You’ll see a tiny circle appear next to the Pen cursor.
Click to turn this final point into a corner point, or click and drag to create one last curve (see Figure 13.15).
An open path, on the other hand, has a beginning and an end. Figures 13.8–13.14 all show open paths. To finish off a path that you want to keep open, follow these steps:
Use the Pen tool to draw a path, using whatever points you want.
After you’ve clicked to place the last point, click the Pen tool button in the toolbar or the Options bar, or switch to any other tool. The path now ends at the last point you created.
Note: Real, but Not Real
One point to remember when you’re working with paths is that any path you create is not really part of the image, even though paths are saved in the file along with the image. ‘A path is not the same as a line drawn on the canvas; until you add color to it, it’s merely a theoretical line. When you stroke a path, it becomes a visible line. If you fill a path, it becomes a shape.
The next time you click in the image window, you’ll start a new path instead of continuing your previous path. And if you didn’t save your previous path with a new name, the new path will replace it.
Whether you create a path by converting a selection or by drawing with the Pen tool, it usually won’t be perfect. No matter how good you are with the Selection or Path tools, every path needs a little tweaking before it’s ready for prime time. You’ve probably realized this while working through the Try It Yourself exercises in this hour. Fortunately, you can easily alter paths after they are created. Again, you use the Pen tool (and the other Path tools) to do this kind of work.
First, let’s take a look at the different Path tools Photoshop offers. Click and hold the Pen tool’s button in the toolbox (see Figure 13.16).
Pen tool—. You’ve already met this tool; it’s used to create new paths.
Tip: It’s Magnetic...
Remember the Magnetic Lasso that automatically formed a selection marquee around the object you were trying to select? The Freeform Pen has a magnetic option, on the Tool Options bar, that works just the same way. You can use it to draw a path that traces the boundaries of a shape. To turn on this option, click the check box labeled Magnetic to the right of the tool buttons in the Tool Options bar.
Freeform Pen tool—. As its name implies, you can use this tool to draw a freeform path in any shape. Photoshop adds points and handles as you go, so you can go back later and adjust any part of your path that’s not quite what you had in mind. This tool is best used with a graphics tablet, if you’ve got one.
Add Anchor Point tool—. Use this tool to add new points to an existing path.
Delete Anchor Point tool—. Use this tool to remove points from a path while leaving the path itself intact.
Convert Point tool—. Use this tool to change a point’s type after you’ve created it. For example, you can turn a corner point into a smooth point, a smooth point into a combination point, and so on. You’ll learn more about how to use this tool in the next section.
Two Path Selection tools also help you work with paths: the Path Selection tool and the Direct Selection tool. They’re found in the toolbox just below the Type tools. The Direct Selection tool (represented by a hollow arrow) can select and move individual segments of a subpath. The Path Selection tool (the black arrow), on the other hand, always selects and moves all the components of a subpath at once. If you have several subpaths within the same path, the Path Selection tool will move one path at a time. To select all the subpath components of a path at once, Option-click (Mac) or Alt+click (Windows) its thumbnail in the Paths panel.
You can switch between the Pen tool and the Freeform Pen tool in one of two ways: either by clicking and holding down the Pen tool in the toolbar so that the menu of other Path tools appears, or by pressing Shift+P on the keyboard. Press A to switch to the Path tools, and press Shift+A to switch between the Direct Selection tool and the Path Selection tool. If you’re already using a Pen tool, press Command (Mac) or Control (Windows) to temporarily switch to the Direct Selection tool.
Here are a few basic techniques for navigating among and using paths:
To activate a path, simply click its name in the Paths panel, just as you would click a layer to activate it. Active paths show up in your image, as you would expect.
To deselect a path, click its name again or click in the empty area of the Paths panel. This makes the path disappear from the main window.
To delete a path, select the path’s entry in the Paths panel and drag it to the trash button at the bottom of the panel, just as you would to delete a layer.
To create a new path, you can do one of four things: Your first option is just to start drawing with one of the Path tools in the image window. This creates a new work path or, if an existing path is selected, adds to the existing path. If you want to name the path before you draw it, choose New Path from the Paths panel’s menu before you begin. You can also click the Create New Path button at the bottom of the panel to place a new path on the Paths panel. Finally, as you know, you can create a selection and then use the Make Work Path command or button to turn it into a path.
To duplicate a path, click its entry in the Paths panel and drag it to the Create New Path button. This works the same way as duplicating a layer.
What can you do with paths after you’ve gone to all the trouble of creating them? Quite a lot, actually. Paths can represent selections that you want to use repeatedly. You can fill a path area or give it a stroke with your choice of color and width, and you even have a tool to apply the stroke. Stroking adds a stroke of paint on the current layer along the path, filling places inside the path with a color or pattern. Figure 13.17 shows a freeform path that has been stroked with red and filled with a pattern. Finally, you can use a path to hide whatever’s outside its bounds, either within Photoshop (a vector layer mask) or when the image is brought into another program, such as Adobe InDesign (a clipping path).
In Photoshop, turning selections into paths is one way to make your selections more easily editable. This can be incredibly helpful when you want to tweak a selection edge or move part of it without moving the rest. When in doubt, create a path so that you can edit the selection one point at a time.
Convert a Path into a Selection
You’ve already learned how to turn a selection into a path. The following steps show you how to convert a path into a selection, whether the path was initially created from a selection or by drawing with the Pen tools:
Start by creating a path using whatever method you prefer.
Click the path you want to convert in the Paths panel to activate it.
Choose Make Selection from the Paths panel’s menu (see Figure 13.18), or click the Load Path as a Selection button at the bottom of the Paths panel. (The latter option bypasses the dialog described in the next step, so if you choose it, you’re done! Photoshop uses the settings you last entered in the dialog box.)
In the Make Selection dialog, set a value for how much feathering, if any, Photoshop should apply to the resulting selection (see Figure 13.19). The higher the Feather Radius setting is, the more partially selected pixels will appear along the edges of the selection.
Click OK, and the new selection appears. The path is still there in the Paths panel, and you can use it again any time you want.
Filling a path means just what you expect. Choose a path in the Paths panel and choose Fill Path from the panel menu; you’ll get the same options you see when you fill a selection, plus a couple of extras. In the Fill Path dialog (see Figure 13.20), you can choose a color, a pattern, or a snapshot to fill the area. You can also choose a blending mode and an opacity percentage, and you can opt to preserve any transparent pixels within the path, filling only pixels that are already painted. You can turn on anti-aliasing, and you can also set a feathering value. If the path consists of two or more subpaths, only the one you select with the Path Selection tool will be filled or stroked.
Stroking a path affects the outline of the path, not the entire area that it encloses. Select a path, and then choose Stroke Path from the Paths panel menu. The Stroke Path dialog offers you a choice of tools with which to apply the stroke, from Pencil and Brush to History Brush and Color Replacement tool (see Figure 13.21).
Whatever tool you pick, Photoshop uses that tool’s current settings to create the stroke. So, for example, if you want to airbrush the path outline with only 60% pressure, make sure that you switch to the Brush tool, turn on the Airbrush option, and set that Flow value in the Tool Options bar before you choose Stroke Path.
Tip: Take the Shortcut
If you hate using panel menus as much as I do, you’ll be happy to hear that the Paths panel contains buttons for both filling and stroking. Position your cursor over the buttons at the bottom of the Paths panel, and you’ll see the ToolTips identifying the buttons’ functions. Press Option (Mac) or Alt (Windows) as you click a button, to open its dialog instead of applying the fill or stroke immediately.
In the last hour, you learned how to create vector layer masks from a path; now you have the skills you’ll need to draw that path in the first place. A layer mask, whether vector-based or pixel-based, hides parts of a layer while letting other parts show through. In the case of a vector mask, everything within the path’s bounds shows, and everything outside the path is hidden.
Vector masks work great in Photoshop, but they often don’t translate into other programs that don’t support Photoshop’s transparency. For example, if you look back at the pressure gauge image at the beginning of the hour (see Figure 13.1), you’ll see that its image window is square. I can use the path I created around the gauge to create a vector mask that will make everything around the gauge transparent, so that a background I place behind it will show around the edges. But if I save this image as a TIFF file and then import it into QuarkXPress, all those transparent pixels will be replaced with white ones.
To make sure that transparency is preserved when you’re using an image in another program, you need to do two things: Designate a clipping path and save your image in EPS format. To assign a clipping path to an image, make sure you’ve given the path a name, and then choose Clipping Path from the panel menu and pick the path you want to use. Then, when you save the image, choose Photoshop EPS for its format.
Note: You Do Have Options, But...
Some design programs support several methods of representing transparency. In addition to clipping paths, you can use alpha channels or layer masks, and, in this case, you’re not stuck with saving the image in EPS format. On the other hand, some older programs can use only EPS with clipping paths for transparency. So to be on the safe side, use the EPS-with-clipping-path method for saving nonrectangular images.
Paths are the key to true precision when creating selections, masks, and shapes in Photoshop. Because they’re based on mathematical equations, not pixel locations, they stay the same shape when you scale them up or down, and they’re infinitely adjustable. You can use paths to save selections for future use, turn them into complex filled and stroked shapes, and mask parts of your image with them. You can create paths from scratch with the Path tools or generate them by converting selections. Either way, editing those paths is a sometimes arcane art that requires you to get used to manipulating curves without actually touching them—but mastering it is a worthwhile pursuit because of the artistic freedom it gives you.
Create a new image file and use the Pen tool to draw both a star-shaped path and a freeform path with a lot of curves. Stroke each of these paths with a color. Then use the Freeform Pen tool in Magnetic mode to trace around them. Notice that as long as you stay close to the original line, the Pen tool places a path right at the edge of the stroke. Fill the new shapes with a color. Draw two more paths inside these shapes, and fill them with a different color. Practice with the Path tools, adding points and refining your paths until you’re comfortable with them all.