What’s the difference between CTB and STB?
You may already know that CTB and STBs are types of plot styles, which can control the way your objects print in AutoCAD. But what you may not know is that each drawing created is either CTB-based or STB-based. You must make a choice; you can’t have a drawing that is both. Starting in AutoCAD 2000, AutoDesk added STB-based drawings as a new plot style option. Prior to that, we could only create CTB-based drawings and plot styles.
In this video, I took a quick look at what the difference is between the two plot style options.
A CTB is a plot style table that has a list of colors. When you change the settings for that color, it controls how everything in the drawing with that specific color will print. Basically, anything that is the same color in the drawing is going to get the same plot style settings, and, therefore, the same result when it prints. Monochrome.ctb is one CTB that comes with AutoCAD. You can see a list of all the colors in AutoCAD from Color 1 to Color 244 by opening the form view. This example is a monochrome which means that every single color is set to print black. However, you can save monochrome.ctb under a new file name and then edit aspects of each color, such as line weight.
An STB is a named style table, and this plot style has a list of style names. You can make as many styles as you want, and then apply them either to a layer or directly to an object. Monochrome.stb is one STB that comes with AutoCAD. By default, this particular STB has two styles: Normal and Style 1. You can have as many styles as you want in a plot style table that’s a named style table. For example, you might have styles called Light, Medium, Medium Heavy, and Heavy. However, you could name them anything you want, and, then, apply them to your elements. The difference with these is that instead of automatically being assigned to a specific color, you could assign this style to any object in the AutoCAD drawing or an entire layer in an AutoCAD drawing. So, in my opinion, STBs are a tiny bit more flexible than CTBs. CTBs, however, are easier to use when standardizing across your organization as they allow you to be a little bit more uniform in your printing as you roll out your drawings.