For decades, draughtsmen, architects, and CAD managers have wrestled with a fundamental challenge when configuring their digital drawing boards: how best to translate on-screen geometry into professional, readable paper or PDF outputs. If your practice is currently navigating a software transition or updating its digital standards, you are likely asking a very specific question: CTB vs STB in BricsCAD: Which Plot Style Should UK CAD Teams Use?
Getting your plotting configuration right is not just about aesthetics; it is about communication, compliance, and efficiency. Whether you are submitting planning drawings to a local council or sharing structural details with a multidisciplinary BIM team, the clarity of your line weights and linetypes is paramount.
In this comprehensive guide, we will explore the nuances of plot styles BricsCAD uses, dissect the core difference between CTB and STB plot styles, and help you decide which system is best suited for your firm’s workflows.
In the realm of CAD, a plot style dictates how the objects on your screen (which are often drawn in bright, high-contrast colours for visibility) will appear when printed. They control line weights, line colours, dithering, and line ends. BricsCAD supports two plot style table formats: colour dependent plot style tables, stored as CTB files, and named plot style tables, stored as STB files. BricsCAD documentation refers to these as CTB and STB plot style tables.
A BricsCAD CTB file is a colour dependent plot style table. It contains 255 plot styles, one for each indexed colour from 1 to 255, and the applicable plot style is selected by an entity’s indexed colour. For example, Colour 1 may be configured to print as a 0.13 mm black line, while Colour 2 may print as a 0.25 mm black line. True Colour entities are not mapped through a CTB table and instead print using their entity properties.
A BricsCAD STB file relies on named plot styles. Instead of linking print properties to the on-screen colour of an object, you assign a specific “style name” (e.g., “Heavy_Outline” or “Thin_Hatching”) directly to a layer or an object. With STB, a red line and a yellow line could both be assigned the “Thin_Hatching” style and print exactly the same way.
The core technical difference is how the plot style is selected. In a CTB drawing, an entity or its layer must use the indexed colour associated with the required plot treatment. In an STB drawing, a named plot style can be assigned to an entity or layer independently of its display colour. Display colour will remain independent of the final output only where the named style defines the required plotted properties.
CTB remains relevant wherever existing templates, client requirements, legacy drawings or established office standards use colour dependent plotting. If you are deciding whether to retain CTB, the main considerations are compatibility, familiarity and the cost of changing an established workflow.
Teams that already use a documented colour to lineweight convention may find CTB familiar because users can associate indexed colours with expected plotted results. During an AutoCAD to BricsCAD migration, existing CTB files can be copied from the AutoCAD Plot Styles folder into the BricsCAD PlotStyles folder and then tested from the Print dialogue. This supports direct reuse of the table, although drawings, page setups, fonts, plotter configurations and output devices should still be checked.
If your architectural or engineering firm has been operating for decades, you likely possess an extensive archive of legacy projects. Opening a project from 2012 to issue a quick revision can turn into a nightmare if you have radically altered your plotting standards.
When dealing with legacy DWG files, retaining the original CTB, page setup and associated plotting resources can reduce reconfiguration and help preserve the intended output. Identical printing is not guaranteed because results may also depend on fonts, external references, plotter configurations, drivers, paper settings and the output device.
A BricsCAD colour dependent plot style table contains 255 fixed styles, one for each indexed colour. Users select a colour and configure its plotted properties. Octave describes CTB as simpler to employ but less flexible than STB. Its suitability depends on the organisation’s standards and exchange requirements, rather than the size of the practice or whether it undertakes BIM work.
STB can benefit organisations that want display colour and plotted appearance to be controlled independently. This can support complex coordination and documentation workflows, but neither UK government policy nor the ISO 19650 series mandates the use of STB.
BS 1192:2007+A2:2016 was withdrawn in January 2019 and replaced by BS EN ISO 19650 Parts 1 and 2. ISO 19650 establishes information management concepts and processes, but it does not prescribe CTB or STB and does not impose one universal CAD layer naming structure on every UK project. Information container naming, classification, layer conventions and plotting requirements should be taken from the applicable client or project information standard.
In a CTB workflow, indexed colour selects the applicable colour dependent plot style. If the office CTB uses colour to control lineweight, changing a layer’s indexed colour for discipline based visual differentiation may also change its plotted treatment. This can complicate visual coordination, although it does not constitute automated clash detection and will not necessarily produce incorrect lineweights if the CTB has been designed for the chosen colours.
By using named plot styles, an organisation can separate layer display colour from plotted treatment. For example, architectural and structural layers may use different display colours while sharing a named style such as “Standard_Wall_0.35”. This does not by itself create compliance with BS 1192 or ISO 19650. Compliance depends on meeting the applicable information requirements and project information standard, while the final plotted result must be verified through page setup and output checks.
STB allows named plot styles to be assigned independently of indexed display colour, and layers may also use True Colour values. This gives teams greater freedom to use colour for screen based identification while named styles control plotted properties. The output is not automatically monochrome or standardised, however. The selected STB, its style definitions, the page setup and the Plot with plot styles option must all be configured and checked.
When standardizing plot styles for UK engineering firms or architectural practices, CAD managers must establish robust CAD printing standards.
If you choose to implement STB, keep your named styles intuitive and limited in number. A good standard for named plot styles might look like this:
Whether you choose CTB vs STB, the key is documentation. Create a clear internal manual that outlines exactly how layers, colours, and plot styles interact within your BricsCAD environment.
To enforce these standards, you need to know your way around the software’s plotting backend. Setting up plot style manager in BricsCAD is a quick process.
Whether you are tweaking a CTB or an STB, you will need to use the Plot Style Table Editor.
If your practice has decided that the benefits of using STB for BIM workflows outweigh the comfort of CTB, you do not have to start from scratch. Many CAD managers inevitably ask how to convert CTB to STB in BricsCAD to future-proof their practice.
BricsCAD makes this transition simple with two specific commands:
Step 1: Convert the Plot Style Table (CONVERTCTB) You cannot simply rename a .ctb file extension to .stb. You must convert the table itself.
Step 2: Convert the Drawing (CONVERTPSTYLES) A DWG file is hardcoded to be either a CTB drawing or an STB drawing. You cannot mix both in a single file.
Even with rigorous CAD printing standards in place, things can occasionally go awry. Here is how to handle the most common issues UK CAD teams face.
Fixing inconsistent line weights in BricsCAD prints is a frequent request for IT support. If your PDFs or physical prints are coming out with incorrect, faint, or overly thick lines, check the following:
A single DWG uses either CTB or STB mode, not both. When consultant drawings use a different mode, one possible workflow is to attach them as external references rather than converting the source files. In an STB host drawing, named plot styles can be assigned to external reference dependent layers. Set and document the required external reference layer overrides, ensure VISRETAIN is enabled where those changes must persist, and test the complete plotted output. This is one available workflow rather than a universal best practice.
So, returning to the ultimate question: CTB vs STB in BricsCAD: Which Plot Style Should UK CAD Teams Use?
You should normally retain or choose CTB if:
You should consider STB if:
BricsCAD supports both CTB and STB workflows and can reuse CTB and STB files migrated from AutoCAD. Successful output still depends on the drawing’s plot style mode, the availability of the correct table, the assigned page setup, entity properties, plotting options and the output device. Compatibility should therefore be verified rather than assumed.
STB offers greater separation between display colour and plotted treatment, while CTB offers a simpler colour dependent workflow and strong compatibility with established drawings and client standards. No authoritative evidence was found showing that STB is becoming the universal future standard for UK engineering or architectural firms. The appropriate choice depends on project requirements, interoperability and organisational governance.
Understanding the Plot Style Manager, conversion commands and team procedures can improve the consistency of published drawings. Compliance must still be established against the relevant technical standards, client requirements and project information standard, and verified through quality assurance before issue.
Question: What is the core difference between CTB and STB plot styles in BricsCAD? Short answer: CTB selects plot styles through indexed colour, while STB uses named styles assigned to layers or objects. A CTB contains 255 colour dependent styles. True Colour entities are not mapped by CTB. In an STB drawing, display colour and plotted treatment can be controlled independently, provided the named style defines the necessary output properties. Octave describes CTB as simpler but less flexible, and STB as more flexible but more complex.
Question: Which should UK CAD teams choose, CTB or STB? Short answer: Follow the client or project information standard first. Retain CTB where existing drawings, templates, client requirements or external exchanges depend on colour dependent plotting. Consider STB for new, controlled workflows that need display colour to be independent of plotted treatment. Neither BIM nor ISO 19650 requires STB, and both systems require documented templates, correct plot style files and tested page setups.
Question: How can STB support project specific layer and information standards? Short answer: STB separates named plotted treatment from display colour, so layers with different colours can share the same output style. This can assist visual coordination and discipline identification, but it does not perform clash detection and does not itself establish compliance with BS 1192 or ISO 19650. BS 1192:2007+A2:2016 has been withdrawn, while ISO 19650 concerns information management. Layer naming, classification and plotting requirements should be taken from the applicable project information standard.
Question: How do I set up and edit plot styles in BricsCAD (CTB or STB)? Short answer: Use the Plot Style Manager and the Plot Style Table Editor.
Question: How do we convert a CTB-based setup to STB in BricsCAD, and handle consultant files using a different system? Short answer: Convert both the table and the drawing, then manage mixed-supplier files via XREF and layer overrides.
