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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 we 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.

In Chapter 6, we recommend that you limit yourself to the first 9 Standard AutoCAD Colors when defining layers, and not a patchwork of the 255 colors that AutoCAD makes available. If you follow our 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 9 colors, rather than worrying about 255 of them.

For systematic testing of your CTB files, you can download the file named plot_screening_and_fill_patterns.dwg from the AutoCAD 2010

Sample Files group at www.autodesk.com/autocad-samples (LT users, feel free to help yourselves to this file too — it’s not included with the down-

loads at www.autodesk.com/autocadlt-samples). This drawing shows an array of color swatches for all 255 AutoCAD colors. The layouts (such as Grayscale and Screening 25%) demonstrate how different CTB files attached to the same layout produce radically different results.

Named plot styles hold a lot of promise, but there are at least a couple of places — dimensions and tables, for example — where they don’t work as well as traditional color-based plotting. Dimension properties allow you to assign different colors to dimension lines, extension lines, and text. The purpose for this is to allow different parts of a dimension object to print with different lineweights; for example, you can have your dimension text print with a medium lineweight, the same as your annotation text, while keeping extension and dimension lines to a fine lineweight. But because named plot styles are based on objects or layers, you don’t have that lineweight control over individual dimension components. The same limitation applies to tables, where you can set your text to be one color and your grid lines to be another.

If you really get carried away and decide to take advantage of the 16 millionodd 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 — lineweights — to distinguish different kinds of objects.

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356 Part III: If Drawings Could Talk

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 (and we’re going to resist the urge to jump in with a comment about mouse reproduction, especially because these days, most mice are optical), AutoCAD developers had to figure out how to let users indicate lineweights onscreen and on a plot. They came up with two different ways to indicate lineweight:

Mapping onscreen colors to plotted lineweights: We describe this common approach in Chapter 6.

Displaying lineweights onscreen to match what the user can expect to see on the plot: This approach 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.

Plotting with plodders

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If you want object lineweights to control plotted lineweights, make sure that the Plot Object Lineweights check box is selected in the Plot Options area of the Plot or Page Setup dialog box. If you don’t want to plot the lineweights assigned to objects, you must deselect both the Plot Object Lineweights and Plot with Plot Styles check boxes in the Plot or Page Setup dialog box. Selecting Plot with Plot Styles selects Plot Object Lineweights as well.

Controlling plotted lineweights with screen colors

To map screen colors to plotted lineweights, you need a color-dependent plot style table (CTB file), as we describe in the earlier section, “Plotting with style.” 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.

Unfortunately, no industry-wide standards exist for mapping screen colors to plotted lineweights. Different offices do it differently. That’s why it’s so useful to receive a CTB, PCP, or PC2 file with drawings that someone sends you.

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.

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.

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358 Part III: If Drawings Could Talk

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

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.

You can tell whether the current drawing was set up to use color-dependent plot styles or named plot styles by looking at the Properties panel on the Ribbon’s Home tab. If the upper-right drop-down list is grayed out, shows ByColor, and doesn’t display a tooltip, the drawing uses color-dependent plot styles. If this list isn’t grayed out and displays the Plot Style tooltip, the drawing uses named plot styles.

Plotting in color

Plotting the colors that you see onscreen requires no special tricks. In the absence of a plot style table (that is, if you selected None from the dropdown list in the Plot Style Table [Pen Assignments] area in the Plot or Page Setup dialog box), AutoCAD sends color information as it appears onscreen 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 thepreceding 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.

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If your goal is not to plot color, make sure that you set the Color property for all plot styles to Black. If you try to plot colors on a monochrome device, you may find that objects appear in various shades of gray, with lighter colors mapped to lighter shades of gray and darker colors to darker shades of gray. This process of mapping colors to shades of gray is dithering, and it usually is not what you want in a CAD drawing. To override it, use the Plot Style Table Editor, as described in the section “Creating plot styles,” earlier in this chapter, to set the Color option for all colors to Black. (The default setting

is Use Object Color.) If you don’t already have a plot style table that you want to use, select monochrome.ctb for color-based plot styles or select monochrome.stb for named plot styles — both of which come with AutoCAD — from the drop-down list in the Plot Style Table (Pen Assignments) area of the Plot dialog box.

When in doubt, send it out

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