Users who are familiar with Plot Settings may know Plot style table, which is used to control the plotted color, lineweight, etc.  

As we can see in the Layer Properties dialog box that every layer has its Plot Style, shown as below, so what is this Plot Style used for?

What is Plot Style?

Plot Style is not only for layers, it is also a basic property of objects. For example, select an object and open Properties Panel with CTRL+1, we can see there is Plot Style in General, shown as below,

The default Plot Style for objects is ByColor while in the Layer Properties Manager, the Plot Style name for layer corresponds to color, for example, when set to color 7, the plot style is Color_7, when set to red, the plot style is Color_4.

But no matter the Plot Style of objects is set to ByColor or Color_7, we can’t change the Plot Style, but why not, how can we change it anyway?

Click Plot button to open the Plot-Model dialog box, and select a CTB file from the Plot style table,  then click the button to open the “Plot Style Table Editor” dialog box, shown as below,

By default the CAD system uses CTB, and we can see there are 255 available colors appear on the list, from Color 1 to Color 255, making up Color_1 to Color_255 in the Layer Properties Manager.

Since we’re using CTB file, the CAD system automatically uses corresponding plot styles according to layer and object colors, no settings or adjustments are required.