Customers often provide artwork for signs and banners in the form of original logos, sketches, drawings and paintings. If you have a digital camera, bitmapped graphics program (e.g., Photoshop), and a vector-graphic program (e.g., Illustrator), you can easily convert customer-supplied artwork into crisp, scalable vector graphics—which, as a bonus, will have smaller file sizes than comparable bitmapped graphics.

What You Will Need

To capture digital artwork, you will need:

1. Digital camera. Preferably a digital SLR (single-lens reflex camera with interchangeable lenses) of 6 megapixels (MP) or more. As prices decline and quality increases, digital SLRs can be purchased today for up to 10 MP for around $500.

2. Copy stand. A copy stand (Figure 1) holds the camera parallel to flat work you want to photograph. It can also be equipped with lights at a 45-degree angle, which illuminate the subject evenly and eliminate glare from shiny objects.

Figure 1: When photographing artwork, use a copy stand to hold the camera parallel to the work. Lights mounted at a 45-degree angle provide even illumination and avoid reflecting glare into the camera.

3. 18% Gray Card. To determine exposure, you can use the camera’s built-in light meter, an external light meter or trial and error. Cameras’ built-in light meters are tuned to subjects that are medium gray, a gray that reflects about 18% of the incident light. If you expose artwork on white paper, the camera will assume it is gray and underexpose the shot; it will be too dark. To get the correct exposure, place an 18% gray card (Figure 2) on top of the object, set the camera to manual exposure, and meter the exposure on the gray card. Then, remove the gray card and capture the shot. Since the camera’s meter sets the midtone of the photo, you may be able to gain additional contrast by setting the highlight and shadow in Photoshop using the Image > Adjust > Curves or Levels dialog boxes and highlight (white dropper) and shadow (black dropper) tools. Gray cards are available from Kodak and X-Rite.

Figure 2: Use an 18% gray card to set exposure of copy work. If you meter on white paper, the shot will be underexposed and too dark, as the camera assumes scenery is medium gray.

4. Grayscale. A 13- or 21-step grayscale (Figure 3) is helpful for verifying highlight and shadow detail. Place the grayscale next to the object and crop it out later in Photoshop. All steps of the grayscale should be visible. If you want to set the highlight and shadow in Photoshop, you can use the first and last steps of the grayscale, respectively.

Figure 3: A grayscale with 13 or 21 steps helps determine if highlight and shadow detail have been captured. All steps should be visible. To enhance contrast, set the highlight and shadow on the first and last steps, respectively, using the Curves or Levels.

Capture Procedure

1. Place the artwork on the copy stand, mount the camera, adjust the camera’s height above the artwork to fill most of the frame and use the zoom lens to fine-tune the subject framing.

2. Place the grayscale next to the object but far enough away to conveniently crop out later.

3. If your camera has autofocus, turn it on and depress the shutter-release button half way to focus.

4. Place the 18% gray card on top of the subject. Before metering, turn off the autofocus, otherwise it will attempt to focus on the card. Set the exposure so that the camera’s meter reads an exposure value (EV) of 0.

5. Capture the subject with the number of megapixels you require, and in JPEG or Camera Raw format. Camera Raw, the “digital negative” format, allows additional adjustments of the image, such as gray balance, before converting to JPEG.

Masking to Remove the Background

Many artwork objects will stand out and look cleaner if you delete the background of the photo. To delete the background:

1. Open the image in Photoshop. Use the Magic Selection tool (Figure 4) to select either the background or the object, whichever is simpler and more uniform in color. The Magic Selection tool, introduced in Photoshop CS3, uses artificial intelligence to distinguish selected from background areas. To add to the selection, click and drag the Magic Selection cursor. To delete selections, hold the Option/Alternate keys while dragging.

Figure 4: To illustrate the vector-conversion process, we have used a handmade Chinese Sianxi paper cut because it is a complex piece of artwork that is not copyrighted. To remove the background of a captured object, use Photoshop’s Magic Selection tool. Introduced in CS3, the Magic Selection tool uses artificial intelligence to distinguish the selection from the background.

2. If selecting the background, invert the selection to select the object. Save the selection as an alpha channel if desired. When imported into a page-layout program, the background will be masked out.

3. To delete the background, set the background color to white and hit the Delete button. The result will be the artwork against a white background (Figure 5).

Figure 5: The resulting bitmapped image is shown at actual size and enlarged 500% (right). Bitmapped images cannot be scaled very much without showing pixelization. The image in this example is 4.7 MB in size.

4. Save the capture in JPEG, TIFF, or PSD (Photoshop) format.

Converting the Object to Vector

By converting artwork to vector format, you can achieve a simpler or “posterized” look, or a completely monochrome, flat look. Since vector graphics are mathematically defined by points, lines and curves, they are infinitely scalable and have a small file size. To convert the capture into vector format:

1. Open a new document in Adobe Illustrator and place your capture from a JPEG, TIFF, or PSD file.

2. Select the placed capture and use the Object > Live trace function (Figure 6). Options include presets, color, grayscale, and line art.

Figure 6: To convert captured artwork from bitmapped to vector graphic format, which reduces file size and facilitates scaling, use Adobe Illustrator’s Live Trace tool.

3. After live-tracing the object, select the object and choose Object > Live trace > Expand to convert it to vector graphics.
After capturing an image with the proper exposure, removing the background, and converting to vector format, you’ll have a professional-looking graphic that is sure to please the customer.