Glossary/Printing & files
CTB (Color-dependent plot style table)
A plot style file that maps each of AutoCAD's 255 colors to a print appearance (line weight, screening, color override).
A CTB file defines how each of AutoCAD's 255 index colors should look when plotted — for example, printing everything as black regardless of on-screen color, or giving specific colors a heavier line weight. It's the classic, color-based way of controlling plot appearance (as opposed to STB, the newer named-plot-style approach).
Applying a consistent CTB — or different CTBs for different drawing types — across a whole batch is what keeps a plotted set visually consistent even when individual drawings were colored inconsistently.
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