LT On-line: Lesson 18

31 Aug, 2001 By: Mark Middlebrook

Plot Styles, Plotting Lineweights, and Plotting in Color

Page 1: Plot Styles

The previous two lessons introduced you to AutoCAD LT plotting with paper space layouts and plotting to scale. This third installment in our series of plotting lessons covers techniques for achieving different plotted lineweights and other plotting special effects, and plotting in color.

The procedures described here work with AutoCAD LT 2002, 2000i, and 2000, as well as with corresponding versions of AutoCAD. These procedures do not apply directly to LT 98 or AutoCAD Release 14, because plotting changed dramatically in AutoCAD and LT 2000.

Plotting with style
Plot styles were new in AutoCAD and LT 2000, so if you used earlier versions of LT or AutoCAD, you probably aren't familiar with them. They come in two exciting flavors: color-dependent plot styles and named plot styles. Plot styles provide a way to override object properties with alternative plot properties. The properties include plotted lineweight, plotted color, and screening (plotting shades of gray). Figure 1 shows the full range of options. Color-dependent plot styles are based on the standard way of plotting in earlier versions of AutoCAD (before AutoCAD and LT 2000), while named plot styles provide a new way.

Figure 1. Editing a color-dependent plot style table.

The good news is that, in some cases, you won't need to bother with plot styles. If the drawings you want to plot have layer and object properties (especially lineweight) that reflect how you want objects to plot, you can dispense with plot styles. The bad news is that most drawings created with AutoCAD Release 14 / LT 98 and earlier versions require plot styles to plot correctly. Also, most experienced users who upgraded to AutoCAD 2000 or 2000i used color-dependent plot styles to retain compatibility with their old ways of doing things. I expect this trend to continue with AutoCAD 2002. Thus, unless you work completely alone and don't exchange drawings with other people, you'll probably have to deal with plot styles at some point.

The most common reason for using plot styles is to map screen colors to plotted lineweights. If this idea seems completely loony to you, try to suspend judgment until you've read the "Plotting through thick and thin" section later in this lesson.

The second most common reason for using plot styles is to create screened lines on monochrome plots. Lines that are screened display in various shades of gray, rather than in black. Drafters sometimes use screened lines to de-emphasize secondary objects that otherwise would overwhelm the main objects in the drawing. Screening is expressed as a percentage, with 100% being completely black and 0% being invisible.

Using plot styles
If you want objects in your drawing to plot with properties that differ from their display properties, you need plot styles. For example, you may want to plot with different lineweights or colors from the ones you're using for display purposes. Or, as I mentioned in the preceding section, you may need to map display colors to plotted lineweights. AutoCAD and LT group plot styles into plot style tables, each of which is stored in a separate file.

Color-dependent plot style tables live in color table (CTB) files and they map the 255 AutoCAD display colors to 255 plot styles. AutoCAD 2002 automatically attaches the color-dependent plot styles to every object, based on-you guessed it-the object's color. Color-dependent plot style tables are especially handy for mimicking the old color-mapped-to-lineweight plotting approach of AutoCAD Release 14 / LT 98 and earlier releases.

Named plot style tables live in style table (STB) files. After you've created a named plot style table, you create one or more plot styles and give them any names you like. Then you can assign the named plot styles to layers or to individual objects.

Note: "Named" refers to the plot styles, not to the tables. Both color-dependent plot style tables and named plot style tables have names, but color-dependent plot styles don't have names and named plot styles do have names. Confusing? I think so.

To use a plot style table and its included plot styles (whether they're color-dependent or named), you must attach it to model space or a paper space layout. The plot style table then affects plotting only for that tab. This approach lets you plot the same drawing in different ways by attaching different plot styles to different tabs. (This is one of the many ways in which AutoCAD LT gives you great flexibility at some expense in additional complexity.)

To attach a plot style to model space or a paper space layout, select its tab at the bottom of the drawing area, open the Plot dialog box, and choose the plot style table name in the Plot Style Table (Pen Assignments) area on the Plot Device tab. See "Controlling plotted lineweights with screen colors," later in this lesson, for an example.

Note: The Plotting tab on the Options dialog box contains a setting called Default Plot Style Behavior For New Drawings. When you start a new drawing using the Start from Scratch option, the current value of this setting ("Use Color Dependent Plot Styles" or "Use Named Plot Styles") determines whether you can choose CTB or STB files. The AutoCAD LT 2002 default setting is Use Color Dependent Plot Styles. When you start a new drawing using the Template option, the template drawing's plot style behavior determines whether you can choose CTB or STB files. Unfortunately, changing the Default Plot Style Behavior For New Drawings setting in the Options dialog box does not change the setting for the current drawing. If you want to change from color-dependent plot styles to named plot styles (or vice versa), use the Convertpstyles command.

Creating plot styles
If you're really lucky, you won't need to use plot styles. If you're somewhat lucky, you'll need to use plot styles, but someone will provide the plot style table files for you. If that's the case, you must put the CTB or STB files in the AutoCAD or LT Plot Styles folder (for example, \Program Files\AutoCAD LT 2002\Plot Styles) in order for AutoCAD to recognize them.

If you're not lucky at all, you'll have to create your own plot style table files. Here's how:

1. Choose File, then Plot Style Manager.

The Plot Styles folder opens in a separate window.

2. Double-click the Add-A-Plot Style Table Wizard program shortcut.

3. Read the opening screen and click Next.

4. Choose the Start From Scratch option, or one of the other three options if you want to start with settings from another file. Then click Next.

The remaining steps in this procedure assume that you chose Start From Scratch. If you chose another option, simply follow the wizard's prompts.

Tip: If the creator of a drawing provides you with an AutoCAD Release 14/LT 98 PC2 (version 2) or AutoCAD Release 12/LT 95 PCP (version 1) file, choose the Use A PCP Or PC2 File option. With this option, the wizard imports color-to-plotted-lineweight settings automatically.

5. Choose whether you want to create a color-dependent plot style table (CTB file) or a named plot style table (STB file). Then click Next.

Choose Color-Dependent Plot Style Table to map screen colors to plotted lineweights. Choose Named Plot Style Table so that the colors plot as you see them on the screen and to create named plot styles that you can apply to layers or objects.

6. Type a name for the new CTB or STB file and then click Next.

7. Click the Plot Style Table Editor button.
The Plot Style Table Editor dialog box opens (refer to figure 1).

8. If you created a color-dependent plot style table, assign Lineweight, Screening, or other plot properties to each color that's used in the drawing. If you created a named plot style table, click the Add Style button and then assign plot properties to each of the named styles that you create.

Tip: To determine which colors are used in a drawing, switch to the AutoCAD window and open the Layer Properties Manager dialog box by clicking the Layers button located on the Object Properties toolbar.

Another tip: To change a setting for all colors or named styles in the Plot Style Table Editor dialog box, click the first color or named style to select all of them, hold down the Shift key, then click the last color or named style. Any subsequent changes you make are applied to all of the selected colors or named styles.

9. Click the Save & Close button to close the Plot Style Table Editor dialog box. Then click Finish to complete the steps for the wizard.
The Plot Styles folder now displays your new CTB or STB file.

10. Close the Plot Styles folder by clicking on the X in its title bar.

Creating your first plot style table can be a harrowing experience, because you have so many options. Just remember that your most likely reason for creating one is to map screen colors to plotted lineweights (as I describe in greater detail in the next section). Also remember that you may be able to minimize your effort by getting a PCP, PC2, or CTB file from the person who created the drawing that you want to plot.

Tip: For standing drafting work, I recommend that you limit yourself to the first 9 Standard AutoCAD Colors when defining layers, rather than using a patchwork of the 255 colors that AutoCAD makes available. The additional colors are useful for rendering, where you want more subtle color variations. If you follow my advice, your work to create a color-dependent plot style table will be much reduced, because you'll have to assign plot properties for only nine colors, rather than worrying about 255 of them.

Plot Styles, Plotting Lineweights, and Plotting in Color
  Page 1: Plot Styles
  Page 2: Plotting Lineweights
  Page 3: Plotting in Color

About the Author: Mark Middlebrook

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