Working with the Ruler and Units:
Using the ruler does not affert the quality of your finished product. The ruler does help keep your project consistent with the measurment of your output size. By using the Ruler Units it offers you precise information on the width and the height of what you are working on. The use of the Column measurements provides information that will help when creating something with columns, a newspaper, magazine, or brochure. Creating a New Document, you can preset the resolution and the specific size of the document by entering the values.
The Options for the Rulers and Units:
For Windows - Edit > Preferences > Units & Rulers
For Mac - Photoshop > Preferences > Units & Rulers
• Select the Units options you want to use:
○ Rulers. Sets a default measuring system for the Ruler bar.
For example, pixels would be most common for images displayed on a monitor, and picas or inches most common for output to press or printer.
○ Type. Use to measure type with pixels, points, or millimeters.
You can switch between ruler measurements without going to Preferences. To change the default measurement of the Ruler bar, go to the Ruler bar, and then right mouse click. Chose from the list of available measurement.
• Select the Column Size settings you want to use:
○ Width. Choose a measurement system and numerical value for column width.
○ Gutter. Choose a measurement system and numerical value for gutter (the space between the columns).
When you choose a measurement system (points, inches, or centimeters), Photoshop changes the value to correspond to the type of measurement system.
• Select the New Document Preset Resolutions settings you want to use:
○ Print Resolution. Select a print resolution and measurement value for default printing.
○ Screen Resolution. Select a print resolution and measurement value for default screen display.
• Click the PostScript or Traditional option measuring systems for Photoshop’s type tool (PostScript is the most widely used).
• Click OK to set your preferences.