Plotting Lineweights and Colors

In previous sections of this chapter, I help you gain some plotting confidence. Those sections show you how to create scaled, monochrome plots with uniform lineweights in model space or paper space. Those skills may be all you need, but if you care about controlling plotted lineweights and colors or adding special effects such as screening (plotting shades of gray), read on.

Plotting with style

Plot styles provide a way to override object properties with alternative plot properties. (See Chapter 6 for information about object properties.) The properties include plotted lineweight, plotted color, and screening (plotting shades of gray). Figure 16-7 shows the full range of options. Plot styles come in two exciting flavors:

• Color-dependent plot styles
• Named plot styles

Color-dependent plot styles are based on the standard way of plotting in earlier versions of AutoCAD (before AutoCAD 2000), whereas named plot styles provide a newer way.

Figure 16-7: Editing a color-dependent plot style table.

It's remotely possible that 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. But most people and most drawings use plot styles, so you should at least be familiar with them.

A couple of common reasons for using plot styles are 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, a bit later in this chapter.
• Create screened lines on monochrome plots. Lines that are screened display in various shades of gray, not 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 percent being completely black and 0 percent 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 can plot with different lineweights or colors from the ones you're using for display purposes. Or, as I mention in the preceding section, you may need to map display colors to plotted lineweights. AutoCAD groups plot styles into plot style tables, each of which is stored in a separate file.

Color-based plot styles live in color-dependent plot style table (CTB) files, and they map the 255 AutoCAD display colors to 255 plot styles. AutoCAD automatically attaches the color-dependent plot styles to every object, based on — you guessed it — the object's color. (Are those AutoCAD programmers brilliant, or what?) Color-dependent plot style tables mimic the old color-mapped-to-lineweight plotting approach of AutoCAD R14 and earlier releases; this remains the most common method in most companies.

Named plot styles were introduced in AutoCAD 2000, and are object properties, just like color, linetype, and lineweight. Named plot styles live in (wouldn't you know it?) named plot 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. (See Chapter 6 for more information about object and layer properties.)

To use the plot styles in a plot style table (whether they're color-dependent or named), you must attach the plot style table to model space or a paper space layout. The attached plot style table affects plotting only for that layout or for model space. This approach lets you plot the same drawing in different ways by attaching different plot styles to different tabs.

You can attach a plot style to model space or a paper space layout by selecting its image in the Quick View Layouts panel and opening the Plot dialog box, or by right-clicking over an image and choosing Page Setup Manager, then clicking the Modify button. Choose the plot style table name in the Plot Style Table (Pen Assignments) area of the expanded Page Setup or Plot dialog box. See the section “Controlling plotted lineweights with screen colors,” later in this chapter, for an example.

Creating plot styles

If you're lucky, someone will provide you with the plot files you need. If that's the case, you must put the CTB or STB files in your Plot Styles folder in order for AutoCAD to recognize them. (To find the location of your Plot Styles folder, open the Options dialog box, choose the Files tab, and look for the Printer Support File PathPlot Style Table Search Path setting.)

If you're not lucky, you'll need to be smart — that is, you'll want to know how to create your own plot style table files. Here's how:

1. Click the Application button to open the Application Menu, choose Print, and then choose Manage Plot Styles.

   Use the tiny down arrow at the bottom of the list to scroll further down if necessary. The Plot Styles folder opens in a separate Windows Explorer window.

2. Double-click the Add-a-Plot Style Table Wizard program shortcut.
3. Read the opening screen and then click Next.
4. On the Add Plot Style Table – Begin page, 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.

   If the creator of a drawing provides you with an AutoCAD R14/AutoCAD LT 98 PC2 (version 2) or AutoCAD R12/AutoCAD 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. On the Add Plot Style Table – Pick Plot Style Table page, 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 in order to map screen colors to plotted lineweights. Choose Named Plot Style Table in order to create named plot styles that you can apply to layers or objects.

6. On the Add Plot Style Table – File Name page, type a name for the new CTB or STB file and then click Next.
7. Click the Plot Style Table Editor button on the Add Plot Style Table – Finish page.

   The Plot Style Table Editor dialog box opens to the Form View tab if you're creating a color-dependent plot style table (refer to Figure 16-7), or to the Table View tab if you create a named plot style table.

   If you choose a named plot style in Step 5, the Plot Style Table Editor dialog box opens in Table View, with one plot style named Normal in the first data column, a blank column to its right, and Add Style and Delete Style buttons at the bottom. New named plot styles that you create continue to be added in columns to the right of the previous column. For more information, click the Help button in the Plot Style Table Editor.

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.

   To determine which colors are used in a drawing, switch to the AutoCAD window and open the Layer Properties Manager palette by clicking the Layer Properties button located on the Layers panel of the Ribbon's Home tab.

   To change a setting for all colors or named styles, select them all first by clicking the first color or named style, holding down the Shift key, scrolling to the end of the list, and then clicking the last color or named style. Any subsequent changes you make get applied to all 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 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 CTB or STB file from the person who created the drawing that you want to plot.

If you really get carried away and decide to take advantage of the 16 million-odd colors in AutoCAD's True Color or Color Book modes, you're not going to be controlling lineweights with color-dependent plot styles. CTB plot styles affect the lineweights only of objects that use the traditional 255 colors of the AutoCAD Color Index set. If you want True Color or Color Book colors, use object lineweights or named plot styles to control plotted lineweight.

Plotting through thick and thin

Long ago, manual drafters developed the practice of drawing lines of different thicknesses, or lineweights, in order to distinguish different kinds of objects. Manual drafters did it with different technical ink pen nib diameters or with different hardnesses of pencil lead and varying degrees of pressure on the pencil. Because a computer mouse usually doesn't come with mouse balls of different diameters, the AutoCAD developers had to figure out how to let users indicate lineweights on-screen and on a plot. They came up with two different ways to indicate lineweight:

• Mapping on-screen colors to plotted lineweights. I describe this common approach in Chapter 6.
• Displaying lineweights on-screen to match what the user can expect to see on the plot. This approach first appeared in AutoCAD 2000.

Controlling plotted lineweights with object lineweights

Plotting object lineweights is trivial, assuming that the person who created the drawing first took the trouble to assign a lineweight property to layers or objects (see Chapter 6 for details). Just make sure that the Plot Object Lineweights check box in the expanded Plot dialog box is selected. You may also want to deselect the Plot with Plot Styles check box because plot styles can override the object lineweights with different plotted lineweights. You can also make these settings in the Page Setup dialog box for the appropriate Layout or Model tab. To access the Page Setup Manager, right-click the Quick View Layouts button on the status bar and choose Page Setup Manager.

Controlling plotted lineweights with screen colors

To map screen colors to plotted lineweights, you need a color-dependent plot style table (CTB file), as I describe in the section “Plotting with style,” earlier in this chapter. If you're plotting a drawing created by someone else, that someone else may be able to supply you with the appropriate CTB file or, at least, with a PCP or PC2 file from which you can create the CTB file quickly. At the very least, the creator of the drawing should be able to give you a printed chart showing which plotted lineweight to assign to each AutoCAD screen color. Use the instructions in the “Plotting with style” section to copy or create the required CTB file.

After you have the appropriate CTB file stored in your Plot Styles folder, follow these steps to use it:

1. Click the Quick View Layouts button on the status bar to open the Quick View Layouts panel. Move the mouse pointer to the image of model space or the layout that you want to plot.

   As you move the pointer over each image panel, icons for the PLOT and PUBLISH commands appear at the upper corners.

2. Click the Plot button in the upper-left corner of the selected image.

   The Plot dialog box opens. Click the More Options button if the dialog box doesn't open in expanded mode, as shown in Figure 16-8.

3. In the Plot Style Table (Pen Assignments) area on the Plot dialog box, select the CTB file from the drop-down list, as shown in Figure 16-8.

   This action attaches the plot style table (CTB file) to the layout or model space tab that you clicked in Step 1.

   

   Figure 16-8: Selecting a plot style table that maps screen colors to plotted lineweights.

4. Click the Apply to Layout button.

   AutoCAD records the plot setting change with the current layout's configuration information. Assuming that you save the drawing, AutoCAD uses the CTB that you selected as the default plot style when you (or other people) plot that layout in the future.

5. Continue with the plotting procedures described earlier in this chapter.

If your drawing uses a named plot style table instead of a color-dependent plot style table, you follow the same procedure, except that you select an STB file instead of a CTB file in Step 3.

Plotting in color

Plotting the colors that you see on-screen requires no special tricks. In the absence of a plot style table (that is, if you selected None from the drop-down list in the Plot Style Table [Pen Assignments] area in the Plot or Page Setup dialog box), AutoCAD sends color information as it appears on-screen to the plotter. As long as your output device can plot in color, what you see should be what you get.

If you attach a plot style table to the layout that you're plotting (as described in the previous section), you can — if you really want to — map screen colors to different plotted colors. In most cases, you don't want that kind of confusion. Instead, leave the Color property in the plot style table set to Use Object Color.