CADDManager on August 24th, 2009

Do you use STB or CTB?  CTB has been around since day one of AutoCAD.  Most users may not even know that they use it – but they do.  STB is newer but has been around for a while.  But it has not taken over the AutoCAD world by storm.

If you are trying to choose which one to use there are some good things and bad things about each.  Here are a few…

CTB Advantages:

  • Most legacy drawings use CTB
  • You are most likely have already got this down pat.
  • It is used by most CAD users
  • Most CAD users “eyes” can quickly define thickness by color

STB Advantages:

  • STB has a shorter list of options when picking pen weights. Users will not have to guess or refer to a chart to see what color number to use.
  • When using STB you don’t have to remember what color equals what weight.
  • Ability to plot layers that use the same colors with different line weights, screening values, colors etc.
  • Since you really only use about 5 or 6 different line weights and a couple of screening values, you won’t have to manage 255 color settings of a CTB file
  • SketchUp and Revit do not use pen weights. You would be moving toward simplification of plotting options.

Neutral Issues:

  • You can swap either CTB or STB easily to create a different plot look.
  • E-transmit sends all of the stuff needed. When you send out the border and sheets the plot table goes along.
  • Exchanging PDF files for updates so CTB or STB does not matter.
  • Exchanging files can be done with DWF Underlay or PDF – no adjustments needed on pen weights.
  • Autodesk is not pushing one way or another.  Development on both is more or less stagnant.

STB Negatives:

  • STB Plot style name may not be easily understoodOthers may not understand them outside your firm.
  • The conversion of existing data to STB will take time
  • STB not as widely adopted in general.
  • Getting everyone up to speed on using STB files may take time.

CTB Negatives:

  • 255 colors promised but not all can be used since some cannot be used.
  • You have to manage all 255 colors
  • users can pick all over the map from the 255 colors/weights

15 Responses to “CAD Standards – CTB vs STB”

  1. My feeling is that the STB method has not gained acceptance because it does not really add anything new or better to what you could always do with the color system all users have used for so many years. I have always lived by one important rule, do not do it just because AutoCAD can. If it added something to my process I would have adopted it when it came out, but I have never found a good use.

    Additionally, you mention the advantage to a CTB is the ease of identifying color as being a set line weight. I think this is the most important reason for using this system over the STB method. Now you could say that none of this matters so long as the elements are layered correctly, and that may be ok for certain drawings. Still, when I look at a drawing I can see if things are correct by the colors I see. I do not need to list their layer or line weight.

    As far as the 255 colors to manage, I do not see this as any king of negative, unless you really try to use that many. Like you mentioned there are only a small number of line weights and shading needed, so we only use a small number of colors. We do have some overlap of colors; Colors which have the same line weight assigned; and that is to differentiate the type of object and thus the layer it is assigned.

    Now, you can do all of the same things with the STB. You could even still use color to help to quickly identify objects, but why do it twice. It seems like AutoDesk is complicating something that has always worked. Now, I could just not see the benefits and I am always open to new ideas.

  2. I still don’t understand which is which. I specify colors and lineweights via layer properties, so what I see on screen is what gets printed. Is that STB, CTB or neither?

  3. 2 Jen.
    You use none of these plot styles. Plot styles are handy when you work in a firm, i think.
    Now i’m trying to switch to STB method. But there is one problem i can’t fix – if you have some plot style named “bold” and you rename it, for example, to “thin” – you get it missed in all of your drawings that use this plot style and you have to fix this problem in all your drawings. There’s no such a problem in CTB method
    As to CTB negative – this system is rather connected with display color; some users prefer to draw on grey background – and some colors are very pale in that case
    So i’m not sure what method is the best

  4. I converted over to aec standard.stb (included with ACA v 7 I think) and would never go back to .ctb. Doing 3d work, colour can be important in quick renderings and being tied to colour is not helpful. aec standard.stb is different from the other stb files in that the pen thickness is in the layer and not the plot style. This simplifies it’s use considerably and makes available the thickness dialogue box which is there but unused with ctb’s unless you are outside the 256 colours. I am now converting a drafting service over to the same stb and it is easy to convert except where blocks don’t have a plot style defined or it’s some weird style like ‘style 6’ which is meaningless like ctb’s. aec standard.stb has simply, ‘Full Saturation’ 50%, 25%’ OR ‘Standard’ which will print colour. EASY! pen thickness is defined in your layer or easily overriden for an item if you don;t want thousands of extra layers. ie. you can have thick and thin lines on a wall layer without worrying about it. From my understanding, the original stb’s didn’t really simplify things and is why it’s not been accepted as well as it should. aecstandard.stb I believe is an excellant option for an office looking to convert. Problem is I think that it’s in the ACA installation but not standard autocad! 🙁 They get it wrong again!! Using this stb frees you to use whatever colors helpful to you for onscreen display and helpful to sort layers etc (i.e. some have poor sight or colourblindness). Use your page setup in black and white to view your penthicknesses like you should. Colour your layers along your pen thicknesses if you need to! You are free to do so!!!!!

  5. “255 colors promised but not all can be used since some cannot be used.”

    Nice explanation. !?!?

    Your posts are so vague and general they don’t provide anything to advanced users, and I don’t think they’re specific enough for new users either.

    This is definitely a quantity over quality blog. yuck!

  6. Ted,

    “255 colors promised but not all can be used since some cannot be used.”

    a little more…

    Some colors cannot be used because they do not show up on screen. The color is too dark.


  7. I don’t think everyone gets the importance of color in 3D work. When you are sharing 3D models between disciplines or with contractors, the only things they can see are shape and color (sometimes layers). Since color is tied to plot settings in CTB, you are not free to use color to enhance the communication of a design or to indicate phases of construction.

    Named Plot Styles (STB) makes the use of color a much more flexible task, since the plotted drawings will not be dependent on color to plot correctly.

    My opinion is that if you do all your work in 2D, then there is not much advantage to use STBs – although there is still some advantage. If you do your designs in 3D, however, you are missing the boat entirely by using CTBs. Having the freedom to use color as you see fit is a big deal.

  8. No one has mentioned yet that CTB will give you one clip access to monochrome printing which is quite simple to do. STB doesn’t seem to support it at all.

  9. Thanks for the great article – it was very helpfull.
    I’ve got you added to my Favorites. Great website
    Thanks again
    Louis Duenweg

  10. I love using named plot styles. Converting a ctb file to a stb file makes converting older drawings to style based, but pointless, unless you want to send a full sheet set through the SSM to an override plotter and the full sheet set needs to use either ctb or stb.

    One of the biggest advantages to named plot styles though, is that it allows you to plot a 3D poly line as dashed, centerline or phantom, Same goes for Civil 3D feature lines for that matter. This is a huge advantage that color based cannot do as of now.

  11. I use a ctb file. I have received a dwg from another firm and they use an stb file (not well, I might add). Can I change the drawing to accept a ctb file instead of the stb file? I don’t even know where to start.

  12. I’ve used .ctb plot styles since 1992 (over 20 years) and initially I was not keen on changing to .stb plot styles. However, the one benefit I see with .stb is as follows –

    If I’ve got a cross hatching (ans137) to be colour red (10 in .ctb), and in one section of a drawing I want it to be thick/bold lines where as another section I want it to be thin lines to the same scale and colour, I can easily do that with .stb plot styles, but not with .ctb plot styles. In general, with .stb it’s easier to control the thickness of the hatching lines when they need to be coloured rather than just black.

    This has made me change to using .stb now which I’m glad of.

    To help with the change, in Layer Property Manager I list all the layers by the Plot Style column, and adjust the colour to match e.g. Al ‘Plot 1’ styles become ‘red’ in colour, all ‘Plot 2’ styles become ‘yellow’ in colour etc. This aids the CAD users “eyes” when working, and takes under a minute to do.

  13. Using CTB is fine for some situations, but you have to be willing to give up the flexibility that STB offers. With STB any object or any layer can be plotted as any color or any lineweight. It is easy to have different objects on one layer plotted or not plotted. The same can be said for screening. Objects or whole layers can easily be screened and plotted in any color. The choice is completely yours as you develop your drawing. CTB is very restrictive concerning those options. CTB is a holdover from the old pen plotters days. I just don’t understand why the antiquated system of CTB has not faded away for the more robust, flexible STB system. If more people used the STB then the only reason for using the CTB would go away.

  14. If I would like to Keep using CTB, what is the best solution for the issue that I am using the same Color for different objects/in different layers?

    With STB that is much easier, I think!
    Any help? 😀


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