AutoCAD - What is the point of a CTB file?

[fkuznets]

I'm new to AutoCAD, so sorry if this is a bit of a silly question, but aren't CTB files redundant? Why would I ever need to use them? From what I understand, they're just a way to assign a bunch of properties to things in my drawing, but couldn't I just do that using layer properties? 

[ The subject line of this post has been edited for clarity by @handjonathan Original: What is the point if a CTB file? ]

[pendean]

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@TomBeauford wrote:

...We use an STB with only ...

...If you know some way of making CTB plot styles...

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Hate to break up the 'shaming' party... STB or CTB (or neither) remains a user choice, most likely set by the method that makes most sense for that person in charge of making that decision/direction.

If you believe there is only one single true way and everyone else is wrong, then it may be a good time to socialize with other equally adamant AutoCAD users that do it quite differently. The burden of conviction and proof remains within you alone, it's not for anyone else to prove/convince you otherwise.

[TomBeauford]

I pointed out that "To use plot styles to control lineweights requires multiplying the number of plot styles you actually need by the number of different lineweights you might possibly use" which is true for both STBs and CTBs and was told in a reply it wasn't true so I replied asking how they could do that without adding extra plot styles honestly wanting to know if they had an answer.

Am I missing something? It seems the post I replied to has been taken down so feel free to take down my response to the post that's no longer there if you'd like. Until lineweights were added in the 2000 version we all had to use plot styles for lineweights. Before then I had to xref the main drawing in, rename it, then xref it in again on a different layer to be able to modify the layer colors of each so different viewports displaying the same area for different purposes could show different objects with heavy lineweights. With good templates it's easy now for both STBs and CTBs. We went with an STB created by Florida DOT as we're in Florida and seemed like a logical pick.

I've always liked that there's generally at least 3 ways to do anything in AutoCAD.

[RSomppi]

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@TomBeauford wrote:

Am I missing something? It seems the post I replied to has been taken down so feel free to take down my response to the post that's no longer there if you'd like.

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Your posts are still here on the first page of this thread.

[TomBeauford]

Your post saying I was wrong that I replied to is the one I said is no longer here. Hoping it's because you understand now.

[RSomppi]

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@TomBeauford wrote:

Your post saying I was wrong that I replied to is the one I said is no longer here. Hoping it's because you understand now.

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LOL, it's still there on the first page of this thread, you should have a look because I didn't say you were wrong.

This is what I said.

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@RSomppi wrote:
Nope, pretty sure that's not a requirement.

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[pkolarik]

"I pointed out that "To use plot styles to control lineweights requires multiplying the number of plot styles you actually need by the number of different lineweights you might possibly use" which is true for both STBs and CTBs and was told in a reply it wasn't true"

lol.. because it's not true. As was already stated, that's nowhere near a requirement. Like I said previously;  we have two ctbs to manage all our plotting in all instances (and if our plotters/printers played nicely with 100% of the lineweights/shading we'd literally only need one ctb file). In fact, all the companies (very large, and very small) that I've received cad files from in the past have only had one ctb file for all their plotting needs.

[TomBeauford]

OK simple misunderstanding. I was talking about plot styles and you thought I was talking about CTB files. In your CTB file to plot a single color with 5 different lineweights you need 5 different plot styles in your CTB file to do it. You can only use one CTB or STB files at a time to plot a drawing anyway. CTB files have a plot style for each of the original base colors while STB plot styles work are generally assigned bylayer or byblock just like color, lineweight or lineweight. Since they work on all the millions of colors available to AutoCAD only a handful of plot styles are needed, the FDOT.stb we've used for years only has six. Hope that clears it up, glad your STB file works for you.

[RSomppi]

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@TomBeauford wrote:

OK simple misunderstanding. I was talking about plot styles and you thought I was talking about CTB files.

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CTB is a plot style (table). The settings within that file are also called plot styles but not always. They used to be called "Pen Settings".

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@TomBeauford wrote:

In your CTB file to plot a single color with 5 different lineweights you need 5 different plot styles

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CTB's control plotting by color. This cannot be done in a single file.

[cadffm]

@TomBeauford wrote:

In your CTB file to plot a single color with 5 different lineweights you need 5 different plot styles

If we still talking about to controle lweight by plotstyletables only, Right.

You need to draw object in 5 different aci colors, to use 5 different plotstyles, to set 5 different lweight and for all the same color,  you wish to plot (16mio).

- - -

>>but not always. They used to be called "Pen Settings".

Before stb/ctb in the last millennium >25years ago, we had pen settings by *.cfg files or style properties from an existing PCP or PC2 file.

Since 2000, STB/CTB = Plotstyletables, which contains Plotstyles.

[TomBeauford]

Actually cfg, PCP & PC2 files are completely different. We were using CTB files when r12 came out in 1992, not sure which release they came out with.

From AutoCAD 2023 Glossary of AutoCAD Terms:

PC2 file The complete plotter configuration file. PC2 files contain all plot settings and device-specific settings that were saved in previous versions of AutoCAD-based products that run on the Windows operating system. See also PCP file and PC3 file. PC3 file Partial plotter configuration file.

PC3 files contain plot settings information such as the device driver and model, the output port to which the device is connected, and various device-specific settings, but do not include any custom plotter calibration or custom paper size information. See also PMP file, STB file, and CTB file. PCP file Partial plotter configuration file for AutoCAD-based products that run on the Windows operating system.

PCP files contain basic plot specifications and pen parameters that were saved in previous versions. Plot settings that are stored in a PCP file include pen assignments, plotting units, paper size, plot rotation, plot origin, scale factor, and pen optimization level. See also PC2 file and PC3 file. plot style An object property that specifies a set of overrides for color, dithering, gray scale, pen assignments, screening, linetype, lineweight, endstyles, joinstyles, and fill styles. Plot styles are applied at plot time. plot style table A set of plot styles. Plot styles are defined in plot style tables and apply to objects only when the plot style table is attached to a layout or viewport.

PMP file Plot Model Parameter. The file containing custom plotter calibration and custom paper size information associated with plotter configuration file.

[TomBeauford]

A CTB like you use is a file containing multiple plot styles to control plotting by color. While you can have multiple CTB or STB files you can only use one at a time to plot. You clearly understand how to use you CTB but I'm hoping this AutoCAD 2025 Help link clears up how plot styles are stored in them for you: 

About Plot Style Tables from AutoCAD Help

[RSomppi]

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@TomBeauford wrote:

A CTB like you use

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I don't use them. 

I don't need that help. It was a misunderstanding about terminology. That is all. (It's confusing when the same term is used for two things that are closely related.)

[cadffm]

Hi,

>>"Actually cfg, PCP & PC2 files are completely different."

Yes and no, because this was what you had in preR2000 to handle plotter setups (inc. pen settings)

And briefly highlighted: I have only commented on a statement by RSomppi.

>>" We were using CTB files when r12 came out in 1992, not sure which release they came out with."

If you ask me and all resources: CTB (and STB) released with R2000, not R12, not R14, it was 1999 with R2000

*.cfg file contains multiple plotterconfiguration in one file
*.pcp file for temporary pen settings to override plotter configuration
*.pc2 file incl a full plotterconfiguration setup inc. device dependent and independent settings

👍long time ago

[TomBeauford]

Autodesk Plan to Plot: From Page Setup to Output

Plotter Configuration Parameter versions. •. PCP file introduced in AutoCAD R12 ... External files that are stored with the file extension .CTB (Color Table).

Seems we were both wrong both CTBs and STBs were both around in R12 as described on page 3 Plot Styles. Being able to control lineweights with the Layer Manager simply made STBs more attractive since without needing so many extra plot styles for all the lineweights made using an STB that only needed a small handful of plot styles much simpler. That when I first used them.

[cadffm]

Hi,

Attachment - I'll answer that later,
But I have no idea what you see there. Is everything there as I wrote it? Page3 - No word about R12, that's all about the current world(R2000-now)

>>"Being able to control lineweights with the Layer Manager simply made STBs more attractive"

?

We are talking about controling lweights by plotstyletables and you talking about lweight controle by layers

What does it have to do with the discussion? And why are .stb more attractive than (than what?)

It's the same for .ctb too, since you can controle lweight by layer, objects and plotstyletables, perfect.

The fact is, ctb are fix to the color, stb don't have this limitation - so .stb ist more powerful (in Theorie),

no limitation to the displaying color or vpcolor. That was one of the coolest feature R2000,

But Adesk messed it up again.
Basic editing functions were missing again, workarounds that worked back then don't work anymore.
It's like it has been so often since then: great idea, but Adesk doesn't provide any suitable tools for editing.
(But that's getting too specific for this thread)

[cadffm]

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@cadffm  schrieb:

Attachment - I'll answer that later,

I read it again and my comment is still the same:
Page3 - No word about R12, that's all about the current world(R2000-now)

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I wanted to add the following to my last post, now I was finally able to look it up:

from Help R2000

If you used the Pen Assignments dialog box in previous versions of AutoCAD to map colors to pens for the purpose of plotting lineweights and linetypes, you can reuse those pen assignments in AutoCAD 2000. If you did not use the Pen Assignments dialog box to create special plotting effects, you can plot drawings from previous versions of AutoCAD the same way you plot new drawings.
In previous versions of AutoCAD, you could choose to store pen assignment information in PCP or PC2 files. If you do not have a PCP or PC2 file with pen settings, you can obtain the settings from the AutoCAD Release 14 configuration file (acadr14.cfg). To move these settings to AutoCAD 2000, choose New under Plot Style Tables (Pen Assignments) to run a wizard that will migrate your pen settings. If you are using color-dependent plot styles, AutoCAD creates a color-dependent plot style table and attaches it to each layout in the drawing. The plot style table is saved in a file with a .ctb extension. If you are using named plot styles, the wizard creates a named plot style table in a file with an .stb extension.

NOTE If you used the CCONFIG, HPCONFIG, or OCECONFIG commands to configure CalComp, Hewlett-Packard, and Océ devices, respectively, you can use the wizard to extract linetype and lineweight information from PCP, PC2, or acadr14.cfg files. The wizard cannot extract vendor-specific custom settings, such as end style, join style, fill style, and screening. To plot using these additional custom settings, you must apply them using AutoCAD 2000 plot styles.
The following procedures describe two ways of moving pen assignment information into AutoCAD 2000. The first method creates a color-dependent plot style table. The second method converts your pen assignment information from previous versions of AutoCAD into a named plot style table. For more information about color-dependent and named plot style tables, see "Using Plot Styles."