Preferences  in Photoshop  are used to further customize the Photoshop workspace and how it behaves.  To access Preferences select Edit/Preferences.  The Preferences dialog box appears.  Preferences are divided into 8 categories.  At this point, some of the Preferences may not be clear to you because they relate to concepts covered later in the book.  At this point, we’ll briefly discuss a few of the more important settings.

Customize or change your Preferences  by selecting the Preference  type from the drop-down menu.  Photoshop  currently has a number of preferences unrelated to web development that we will not explore.  What follows is a list of Photoshop’s preferences and recommendations to optimize Photoshop for web development.  We begin with Units & Rulers  to ensure that you use pixels rather than inches as your standard unit of measurement.  You may want to return to the other Preferences settings as you proceed through the material.  Until you familiarize yourself with Photoshop’s environment and some of it functions and features, the purpose of some of the Preferences might not be readily apparent.  Feel free to proceed to the next chapter.

Preferences  - Units & Rulers

Units
Select Pixels .  Pixels are the recommended measurement as they are the standard unit for web site development.  Other options relate to images created for Print.

Column Size
Column Size and Point/Pica Size control Font  attributes.  Leave them at the default settings.

Point/Pica Size
Point/Pica Size is Print related settings.  Leave it a default, Postscript (72 points/inch).

Preferences  – General
General Preferences  include Color Picker , Interpolation, and Options .

Color Picker
Color Picker  is set to Adobe at default.  You can set it to Windows (on Windows based systems) but this limits Photoshop ’s control of color.  Keep it at default.

Interpolation
Interpolation calculates intermediate values when translating or changing image resolution and dimensions.  Keep it at Bicubic.

History States
Choose a number between 1 and 100 to increase or decrease the number of History State s that Photoshop  will commit to memory.  Keep in mind that the more History States you allow the higher the demand on your computer’s memory and processing power.  Stick with the default for now.  We’ll be discussing the History Palette  later in the manual.

Preferences  - Saving Files

Image Previews
To save previews or thumbnails of your images select Always Save in the Image Previews drop-down menu.  You will see these thumbnails when you open and {Single-Click} images stored in a directory using Photoshop ’s Open command.  To save disk space select Never Save.  Select Ask When Saving if you want Photoshop to ask if you desire a thumbnail or not whenever you save an image.

File Extension
Select Use Lower Case to force Photoshop  to save files with lower case file type extensions.  Lower case extensions have become the de-facto standard and are recommended.  UNIX servers are case sensitive so a consistent character-case, upper or lower is important to maintain when using your images for the Internet.

File Compatibility
Check Maximize backwards compatibility in Photoshop  format under File Compatibility to ensure programs or applications that don’t support Photoshop’s Layers  can load the image.  Uncheck to create a smaller file.

Preferences  - Display and Cursors  

Painting Cursors
Select Standard, Precise or Brush Size .  Standard displays an icon of the tool, such as the Paint Brush when you paint on the image.  Precise displays a cross hair and Brush Size represents the size and shape of the brush.  We recommend selecting Brush Size so you can see the area and size your brush will be covering.

Other Cursors
Select Standard or Precise.  Standard displays an icon of the tool, such as the Eye Dropper, and Precise displays a cross hair.  For increased accuracy in editing, we recommend selecting Precise.

Preferences  - Plug-Ins & Scratch Disks
Plug-Ins are extra features that extend Photoshop ’s capabilities.  Filters , for instance are actually Plug-Ins that can be added and removed.

Plug-Ins Folder
By default, Plug-Ins are stored under the Photoshop \Plug-Ins directory.  To change the path select Choose and enter the new path.  However, we recommend you keep the path at default.

Scratch Disks
Scratch Disks are areas of your hard drive Photoshop  uses for memory when physical memory (your RAM) is full.  An image in Photoshop takes approximately 3-5 times its file size.  For instance, if your file takes up 10 Megabytes on your hard drive, Photoshop requires approximately 40 Megabytes of RAM when working with it.  As you work on multiple images RAM requirements increase and Photoshop will begin to use your hard drive for virtual (rather than physical) RAM.  It is recommended that free space on your hard drive for the Scratch Disk equals at least the amount of physical RAM in your system.  If you have 128 Megabytes of RAM for instance, you should have at least 128 Megabytes of storage space on your hard drive for the Scratch Disk.  The greater the RAM and free space the better Photoshop performs.  If you have more than one hard drive, we recommend installing Photoshop on one and designating your Scratch Disk space on another.  Photoshop can have up to four Scratch Disks.  To designate what hard drive will act as your Scratch Disk select the drive letter or volume from the drop down list.  By default, Photoshop uses your Startup hard drive.

Preferences  - Memory & Image Cache

Cache  Settings
The Cache  is an area of memory Photoshop  uses to store low-resolution versions of your images to help with screen updates or refreshes.  Recall that typical computer monitors can display no more than 72 ppi.  If you are working on an image with a high ppi setting Photoshop makes all the editing and modifications in the selected resolution, but does not need to use the higher ppi to display your image on screen.  For web development, you will be working in 72 ppi but we recommend you keep the Cache settings at default.  The Cache Level ranges from 1 – 8, the higher the setting the larger the Cache.  If you are running out of memory, you might want to decrease the Cache value.