Web Graphics v/s Print Media

Most new designers fail to understand the difference between designing graphics for strict digital use (web graphics) as opposed to designing print media. Web graphics most commonly consist of banners, logos, web templates, icons etc. that will never see the light of day on paper. Print media on the other hand should be designed specifically for high quality printing. Some common items you may design in Photoshop and end up printing are business cards, flyers, advertisements, and letter heads.

DPI / Resolution

Failing to set the correct dots per inch (dpi), commonly known as resolution, before you start working on your design is the most common mistake designers make. When you open up a new canvas (document) in Photoshop by going to File > New, the first window that pops up has a field for resolution, which is usually set by default to 72 pixels/inch. This value is telling us that there will be 72 dots (i.e. pixels) for every square inch of the document. 72 dpi is ideal when viewing graphics on a computer screen, however when you are printing a design out on stock, 72 dots per inch is not enough, and will usually result in your graphic looking blurry and pixilated. As you’ve probably already figured, increasing the dpi will result in a higher quality image. For most printing purposes you will want to set the dpi to 300 pixels/inch to obtain a good quality print.

The downside? That X by Y dimensions image that you just entered into your document that took up say 80% of the canvas, will now only take up say 20% of it. Why? This is because you have set the document to contain more pixels for square inch, as such, that X by Y image is still X by Y in dimensions, but now has a much lower resolution compared to your high resolution document/canvas thus ends occupying only a smaller space.

When you print digital images or share them on onscreen, choosing the right resolution for your output is of paramount importance. Good ol’ 72-ppi images can be forgiving, and you can get many of your large files scrunched down to 72 ppi for Web sites and slide shows.

Printing images is another matter. Among the many different printing output devices, resolution requirements vary. For a starting point, look over the recommended resolutions for various output devices listed in the following table.

In Photoshop Elements 9, you can select the right resolution for an image in the Image Size dialog box. To access the Image Size dialog box, choose Image→Resize→Image Size.

Avoid resampling up (upsampling) or risk image degradation. When you upsample, you set the new resolution to one that’s higher than the original image resolution without making the relative reduction in width and height dimensions.

Output Device	Optimum	Acceptable Resolution
Desktop color inkjet printers	300 ppi	180 ppi
Large-format inkjet printers	150 ppi	120 ppi
Professional photo lab printers	300 ppi	200 ppi
Desktop laser printers (black and white)	170 ppi	100 ppi
Magazine quality — offset press	300 ppi	225 ppi
Screen images (Web, slide shows, video)	72 ppi	72 ppi

Printing basics

Whether you are printing an image to your desktop printer or sending it to a prepress facility, knowing a few basics about printing makes the print job go more smoothly and helps ensure that the finished image appears as intended.

Types of printing

For many Photoshop users, printing a file means sending the image to an inkjet printer. Photoshop can send your image to a variety of devices to be printed directly onto paper or converted to a positive or negative image on film. In the latter case, you can use the film to create a master plate for printing by a mechanical press.

Types of images

The simplest images, such as line art, use only one color in one level of gray. A more complex image, such as a photograph, has varying color tones. This type of image is known as a continuous-tone image.

Color separation

Artwork intended for commercial reproduction and containing more than one color must be printed on separate master plates, one for each color. This process, called color separation, generally calls for the use of cyan, magenta, yellow, and black (CMYK) inks. In Photoshop, you can adjust how the various plates are generated.

Quality of detail

The detail in a printed image depends on image resolution (pixels per inch) and printer resolution (dots per inch). Most PostScript laser printers have a resolution of 600 dpi, while PostScript imagesetters have a resolution of 1200 dpi or higher. Inkjet printers produce a microscopic spray of ink, not actual dots, resulting in an approximate resolution of 300 to 720 dpi.