The File -> New command is where you set up your digital canvas. How you set your preferences determines not only the basic size of the image, but also in which medium your image can be displayed. While you can always open a new file and change the settings, make sure to set them properly for the intended use of your image.
1. To create a new file, choose File -> New. This command brings up the New image dialog box where you can specify the desired settings. By default, the settings are based on the image dimensions and resolution contained in the Clipboard. If the Clipboard does not contain image data, the image dimensions and resolution are based on the last image that was created.
2. The first choice offered is an input field where you can enter a name for the image. If you choose not to name your image, Photoshop will still create the new image and use the default title in its place instead.
3. You can enter a custom size using the Width and Height input fields, and set the Resolution to a value of either pixels per inch or pixels per centimeter. You can also select the size of the image by choosing from a list of preset sizes, which includes commonly used settings for paper sizes, desktop and Web design sizes, and so on.
4. Select the type of Color Mode for your image from the drop-down menu. The list of choices includes Bitmap, Grayscale, RGB Color, CYMK Color, and Lab Color. Along with the Color Mode, you can also set the Color Depth for the image: 1, 8, or 16 bit.
5. To choose a color for the background layer of an image, select the color you want from the Background Contents list box. The White option fills the background or first layer with white, the default background color. Select the Background Color option to fill the background or first layer with the current background color. The Transparent option makes the first layer transparent, with no color values.
6. If the options for the Advanced settings are not available for a new document, click the triangle button in front of the Advanced heading at the bottom of the dialog box.
7. You can specify a color profile for the new document by selecting a profile from the Color Profile drop-down menu.
8. If you want to change the aspect ratio of pixels for video output, select an option from the Pixel Aspect Ratio drop-down menu. If you deal mostly with print or the Web, you will want to stick with Square as your selection.