the pen
source: http://www.thegoldenmean.com
Introduction to the Photoshop Pen Tool
originally written for the GurusNetwork.com
The Pen Tool. One of the most enduring of Photoshop’s tool set. Stuff of legend and misinformation. The fact that the pen tool has remained nearly unchanged since the earliest versions speaks to the fact that Adobe has this gem just about perfect.
Tedious but Necessary Introduction:
(You are probably accustomed to and expecting a “show and tell” tutorial. This tutorial doesn’t begin the “show” part until page three. Hang in there.)
Although the pen tool is intrinsic to illustration applications such as Adobe Illustrator and Macromedia Freehand, it is not the most intuitive tool for Photoshop born–and–bred artists. The familiar, fluid selection and painting tools don’t apply. I hope to shed some light on the Pen Tool and dispel some of the myth because this really is an industrial strength power tool. I’ll admit that when I’m evaluating a fresh–eyed art school graduate who struggles to make a selection with the Magic Wand when the Pen Tool could do the job better in a fraction of the time, it just screams to me — “no real–world experience!”. Get friendly with this tool.
I won’t undertake an exhaustive exploration of everything the Pen Tool is capable of. As with just about everything having to do with Photoshop, different individuals will use the same tools in different ways. I’m a commercial product photographer, and I’m going to show you how I use the pen tool in a commercial graphic arts environment. I use it for outlining product photos, achieving an astonishingly accurate, infinitely adjustable, perfect fit selection. I’m not a fine artist or an illustrator, but I can help you get comfortable with the basics of the pen tool, and my specific use of it. If your needs are different you can find your own way from there.
Perhaps more than any other of Photoshop’s tools, the Pen demands practice. Even after you “understand” conceptually what it’s all about, the Pen will continue to be frustrating until your hand/eye systems “get it”. There is no way around the requirement to practice. Knowing where to place the points, how far and in which direction to pull out the handles — you can't get that from reading. I’ve got some sample images later on — feel free to download them and work at it. It will pay big dividends later on!
BACKGROUND
But let’s get some preliminaries over with first. Some of you will already know this material but bear with me. In order to discuss what’s so special about the Pen, we need to be clear on the distinction between the two main families of digital graphics (raster graphics and vector graphics), because the pen is all about vectors! (You may also hear this same distinction made using the term “drawing” for vector applications and “painting” for pixel image editors.) Illustrator has some pixel editing tools; Photoshop, one of the premier pixel editing applications of all time, has some vector creation tools. But vectors and rasters blend about as easily as oil and water, and both applications hint at an uneasy alliance between their “non-native” tools.
The term “Raster Graphic” refers to the orderly grid arrangement of pixels. A raster graphic is defined by a specific resolution and a finite number of bits of information — this many pixels across by that many pixels down. It can be thought of as coloring in the squares on a sheet of very fine graph paper. Pixels have a fixed size: enlarge them beyond a certain point and they reveal themselves.
By contrast, the term “Vector Graphic” refers to images which are defined mathematically in the elegant language of Postscript. You'll hear the term “bezier curves” associated with this. A line of a certain length. An arc with a certain slope. Because of the fact that the shapes are described in mathematical terms, vector graphics are not bound by any specific resolution — they scale in size flawlessly, and print to the resolution of a postscript output device, whether that is a 300 DPI laser printer or an image setter laying down thousands of spots per inch.
(More information about Bezier Curves is available from Darrel Plant, who describes a bezier curve as “a simple cubic equation. It is named for Pierre Bezier, who developed it in the ’70s for CAD/CAM but which later became the underpinnings for the Adobe drawing model”.)
PROS AND CONS
With that background out of the way, we can proceed to consider the unique advantages of the Pen Tool. If it is so hard to learn, why bother? Well, let’s start in reverse: what is the Pen Tool not suited for? I’ll be honest. The Pen Tool is a crummy choice for soft–edged selections. If you want to select wispy hair, fuzzy sweaters or a complex mass of tree branches and leaves for example, use another tool.
But on the plus side, the pen tool is unsurpassed for two things: precise, sharp edged selections, and Clipping Paths.
We will explore the first of these arguments at length in the following pages, but let me take a moment to reflect on Clipping Paths. If you work in the world of Print, there is a pretty good chance your images are going to be brought into a page layout program such as QuarkXPress, InDesign or Pagemaker. These are Postscript–based, and Postscript doesn’t understand transparency in the same way Photoshop does. If you bring an image into Quark, it comes in as a picture box — rectangular and opaque. What if the photo is of an irregularly shaped object? Not everything in life has straight edges and 90° corners! If your document’s background is white and your image’s background is also white, that shouldn't be a big issue. BUT - if your Page Layout document's background is a color or a texture, or if the image is going to appear on top of another image, this spells trouble. Imagine the inset image of the perfume bottle product shot superimposed over a grainy, gauzy photo of a frolicking couple in a magazine ad. How do you get the product shot to not show its background? It needs to be saved as a TIFF or an EPS with a clipping path, and that clipping path needs to be made in Photoshop with the Pen Tool.
(Photoshop 6 and higher users should note that Adobe opened the possibility for lots of confusion when they introduced the new vector based Shapes Layer. Shapes on this special layer are bounded by a vector path Adobe calls a Layer Clipping Path. To be completely correct, I should refer to the entity discussed in the preceding paragraphs as an Image Clipping Path. Please be aware of this distinction. Throughout this tutorial, whenever I write “Clipping Path” I am referring to an “Image Clipping Path”.)
If you’re not convinced that the Pen Tool must be part of your professional repertoire, bail out now! Otherwise, let’s get down to business with page 2 - The Tools.
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