AutoCAD - What is the point of a CTB file?
Hi and Welcome to AutoCAD Forum,
CTB, or color-dependent, plot styles are settings for how the 256 available colors in AutoCAD will appear when you plot them, including the lineweight assigned to each color. When you use CTB styles, you are essentially adapting some or all of the colors 0 through 255 to meet your office standards for plotting. You can use Color Plot Styles to plot in black and white or color.
- By using a finite list of layer colors, CTB styles make it easier to tell which layer is which in your drawing and makes it easier to rescale for plotting.
-
The CTB file offers myriad options, but you are primarily concerned with three:
- The color in which the source color should plot
- Line thickness
- Screening
Imad Habash
@rkmcswain wrote:
@fkuznets wrote:
.... 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?
Prior to ~2004 (not sure of exact release), there were no "lineweights" in AutoCAD. So in order to have objects with various widths, we had to use plot styles, or use polylines with a width (and not all objects can be represented with polylines).
Many, dare I say most, people and firms who learned this way still do it this way. As said above, it's a choice.
@fkuznets In addition to what RK mentioned, layers are more for controlling screen appearance, whereas ctp (and also stb) are for controlling plot output. For example, our standard plot size is Arch D. We have a ctb that specifies the lineweights and maps all the layer colors to black. But for a check print (Arch B) we use a ctb that scales the lineweights by half. If all you had were layers, you would have to change the layer settings to get a different plot.
Ed
Did you find this post helpful? Feel free to Like this post.
Did your question get successfully answered? Then click on the ACCEPT SOLUTION button.
How to post your code.
@RSomppi wrote:
@Ed__Jobe wrote:
If all you had were layers, you would have to change the layer settings to get a different plot.Are you sure?
Good catch. oops.
Ed
Did you find this post helpful? Feel free to Like this post.
Did your question get successfully answered? Then click on the ACCEPT SOLUTION button.
How to post your code.
@payingtoomuch wrote:
One of the posts above seems to indicate that there is no way to still see color of the lines in model space when working....
I didn't see that indicated anywhere. Layers have both color and lineweight settings, just like a ctb file has. If you choose "none" for the ctb setting in page setup, then the plot uses the layer settings (and object if it overrides the layer setting). The ctb is just a way to store overrides and easily switch back and forth. Layouts can't completely display what a plot would look like, although you can display lineweights. For that you need to use plot preview. If you want to plot all black, just use the acad-supplied monochrome.ctb.
Ed
Did you find this post helpful? Feel free to Like this post.
Did your question get successfully answered? Then click on the ACCEPT SOLUTION button.
How to post your code.
It depends on your needs, only you would know what works best for you (or your company). But you may want to look at named style table files (stb). Most use color tables because they just never changed from the way that AutoCAD first introduced...too hard to make a change, etc. But named styles have advantages too.
Ed
Did you find this post helpful? Feel free to Like this post.
Did your question get successfully answered? Then click on the ACCEPT SOLUTION button.
How to post your code.
