AutoCAD Color-dependent Plot Style Table
CTB is a file extension for a color settings file used with AutoDesk AutoCAD software. CTB files contain color-based plot styles, or mappings of colors to layers of objects; used to attach color and display settings to design objects. CTB files have been replaced by STB files, though many companies continue to use CTB files due to their compatibility and familiarity. CTB files can be be opened by AutoDesk AutoCAD software.
Learn more about .CTB files:
Visit the AutoDesk web page.
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