One or more of your lines is plotting too thick or thin (heavy or light).
The lineweight setting for that line is likely set incorrectly in the CTB plot style you're currently using.
More information about color-based (CTB) plot styles
To address this issue, you'll need to check, and possibly change, the lineweight setting for the linetype that's plotting incorrectly.
Type PROP in the Command line and press Enter.
Select the line or object that's plotting incorrectly.
Then look in the Properties panel to check the color assigned to the line, and whether the object's Linetype is set By Color or ByLayer. (In most cases, we recommend setting your linetypes ByLayer.)
In our example, the object we've selected is set to the color Magenta (color 6 in the Land F/X color settings) and is set to Linetype ByLayer.
Now open your plotter settings:
Output ribbon, Plot button
type Plot in the Command line.
File menu, Plot option
If necessary, expand the Plot dialog box by clicking the right-facing arrow in the lower right corner.
Select a plot style to edit from the Plot style table (pen assignments) pull-down menu (example: LFX.ctb).
Click the Edit button to the right of the menu.
The Plot Style Table Editor dialog box will open. Select the Form View tab to display current pen assignments of your new CTB file.
To make modifications to your pen settings, select a color from the Plot Styles list and make adjustments accordingly in the Properties panel.
In our example, we'll make a change to Color 6, or Magenta.
The three main settings to check are:
Color: In most cases, this will be set to Black.
Screening: This setting determines the darkness of the plotted color. The higher the screening, the darker the plotted color.
Lineweight: This setting determines the thickness of the selected line color when it plots.
Note that Color 6 is set to an extremely thin lineweight – 0.0300mm – which will cause it to plot as a very thin line.
To change the lineweight in our example, we'll select a new lineweight from the Lineweight pull-down menu (example: 0.35 mm).
Play around with the lineweight setting for the errant linetype until it plots at the thickness you desire.
Examples of Different Lineweights (Plant Outlines)
Here's an example of a drawing with the plant outline layer set to a relatively thick lineweight:
And here's an example of the same drawing with the plant outlines layer set to a thinner lineweight: