Create a Unique Selection

Create a selection by adding and / or subtracting geometric shaped selections. Using your selection as a mask, create two different images: one that defines the positive space, and a second image which will be the opposite and define negative space.

This exercise is designed to familiarize you with the following:

  1. Begin the exercise by creating a new document. Size = 5" x 5", Resolution = 72 ppi, Mode = RGB, Contents = white. Click okay, and be sure that your foreground / background color swatches are set to black and white, the default colors. Press the letter "D" n the keyboard to reset the colors to default black foreground, white background.
  2. Select the Rectangle Marquee tool. Create a selection in the image window‹any size that is smaller than the image window, any shape.
  3. Hold down the shift key and create another rectangular selection.
  4. Keep the shift key depressed. Each time you make a selection with the shift key depressed you add to your existing selection. Once you've created a selection, you need to edit the pixels inside it, or modify the selection and then change the pixels inside of the selection. Some selections are simple, like a fixed-size square or circle, but others are more complex like the one you created here. It may not have been difficult to create the selection, but it would be much harder to duplicate it exactly. At the stage when a complex selection is made, it is important to insure that even if you mess up, you won't have to make that particular selection over again. In order to have that little insurance policy, it's a good idea to save the selection so you can come back to at another time.
  5. Go to the Select Menu > Save Selection.
  6. Type a name for the selection so that if you want to work on the selection again, you will know how to call it up. For our exercise, we will call it floorplan.
  7. Nothing is really saved until the Photoshop document is saved, so go to File > Save. Name your document and save it in the Photoshop format under the "format" popup. The next chapter is dedicated to further explanation of file formats.

This selection was created by holding down the shift key and "adding" rectangular selections again and again. It can be saved and recalled later, by going to Select > Save Selection.

The first part of this exercise concerns itself with creating the selection. The second part of the exercise is about editing the selected pixels. We'll examine several ways to fill a selection.

  1. Choose a new foreground color

 

The color picker displays the current pick in the top swatch, and the previous color in the bottom swatch.
  In the Color Picker you can enter the desired percentages using one of four color models: HSB, RGB, Lab, or CMYK. Press the tab key to highlight successive boxes to specify the color you want. The Color Picker can be used by dragging the slider through the color ramp to the hue you desire. Then click and drag the mouse in the large color swatch on the left adjusting the saturation and brightness.

Three areas of the color picker specifically reference web colors. The small cube shows pops up when the current pick is not web safe*. Click on the cube to arrive at the closest web safe color.
The six-digit number displays the hexadecimal code the current pick.

Click on the check box to display only Web Colors.

Click on the "custom" button in the color picker to choose a custom color. Choose a matching system from the popup menu. The most commonly used matching system in graphic arts is the Pantone Matching System (PMS). Each item in the list refers to a specific book of color chips used for color matching.

Colors can be chosen by typing their reference number, which Photoshop refers to as the "key" number. The CMYK equivalents are indicated below the Key #.

*WEB SAFE COLORS = BROWSER SAFE COLOR
These colors are the only ones that will safely display the same on all browsers and all computer platforms. Due to the various methods browsers use to map and display color, and because most color monitors display only 256 colors, a web safe palette consists of the 216 color common to all.

 

Fill with foreground or background colors - for my money, the easiest and quickest way to fill a selection is to set up the foreground/background colors. Then use these key combinations:

At any time you can load a saved selection by going to the select menu>load selection. Choose the desired selection from the popup menu and click on okay.

To choose all except the selected pixels, go to the Select menu>Inverse.