What are Plot Styles?

[troma]

I'm sorry if this is a hugely basic question. But the terms are quite generic so it is difficult to search for an answer.

This is what I'm talking about:

What are these used for?
Are they something to do with .stb?

We plot with .ctb

I have no idea what these are doing in our template and I'd like to clean house, but I should really get a good idea of what they are first.

Thanks.

[stevetamplen · Accepted solution]

Hello Troma;

This is not a hugely basic question.

When I was a drafter in the late 90's, I don't remember plot styles existing at all in AutoCAD...

The help file can often shed light on some of the more obscure areas of AutoCAD, and I use it often for items I am unfamiliar with. In fact I used it for your question to make sure I was on the mark, since I have never used them in the field. 

Here is the excerpt about plot styles:

A plot style is an object property, similar to linetype and color. A plot style can be assigned to an object or a layer. A plot style controls an object's plotted properties, including

Color
Dither
Grayscale
Pen number
Virtual pen
Screening
Linetype
Lineweight
Transparency
Line end style
Line join style
Fill style

Using plot styles gives you great flexibility because you can set them to override other object properties or turn off the override as needed.

Groups of plot styles are saved in either of two types of plot style tables: color-dependent (CTB) or named (STB).

Color-dependent plot style tables set style based on the color of the object.

Named plot styles can be assigned to an object independent of color.

I hope that helps.

[dgorsman · Accepted solution]

Named plot styles are almost exactly the same as color-based plot styles.  The CTB maps the ACI (AutoCAD color index) to a plot setting - line thickness mostly.  The STB does the same thing but instead of a limited set of integers it uses text-based names.  So instead of a "1" you might have "Object lines"; instead of a "40" you might have "Half-tone (existing)".  The list you are showing is typical of a drawing translated from one type to the other.

These can get inherited from style-based drawing files into color-based files, and you can purge them without any problems.

[troma]

Thanks Steve.

OK, So I may be able to attach a plot style to an object. But in my case I can't.

As you see here in the properties palette, the Plot Style is locked to 'ByColor'. This field cannot be edited.

I presume that this is because I'm working in a .ctb based drawing. All of our drawings plot with color tables, and this is not likely to change.

But with the layers I'm a little more confused.

This is a snapshot of the layer dialog.

Why aren't they also all set to 'ByColor'?

Instead, they are all set to a Plot style that matches their color.

What is slightly more confusing, is that I tested purging them out in this drawing. So all the Plot Styles listed here are in fact already purged out of the drawing. How is that possible?

Perhaps since it is a .ctb drawing, this "attachment" to the layer is ignored and the plot style can be purged regardless.

Apparently the only Color plot style I can't purge are 2 & 7 for whatever reason. This despite the fact that many others are listed in the layer dialog as being in use.

I guess what my question boils down to is this:

Can I purge these from my template (as shown in the OP), or will I live to regret it?

Hey Steve, could you provide a link please to that part of the help? Thanks.

[troma]

Cross posted with you @dgorsman

I think you answered my question, thanks!

[stevetamplen]

I just typed "plot styles" in the help window!