Learn how to add freehand lines for annotations, boundaries, and visual emphasis in your diagrams
Freehand lines allow you to draw custom shapes and annotations directly on your diagram canvas. Use them to highlight areas, create boundaries, add visual emphasis, or organize complex diagrams with clear visual separators.
What freehand lines are and when to use them
How to draw and position custom shapes
Customizing line and fill colors
Best practices for visual annotations
Unlike edges (which connect nodes), freehand lines are purely visual elements for organization and annotation. They're perfect for grouping, highlighting, and adding context to your architecture.
Freehand lines are drawn shapes that serve as visual annotations on your diagrams. They help organize, emphasize, and add context without representing actual architectural connections.
Draw boxes around related components to show grouping
Circle or underline important elements to draw attention
Create visual divisions between diagram sections
Add arrows or pointers to emphasize specific areas
Define system boundaries or deployment zones
Freehand lines are visual-only elements. They don't create connections or relationships between nodes - they just help organize and annotate your diagram.
Creating a freehand line is simple and intuitive. Here's the step-by-step process:
Click "Add line" in the side navigation
Your cursor becomes a drawing tool - click and drag to draw
Move your cursor to create the desired shape
Release the mouse button to finish
The line appears on your canvas, ready for customization
Smooth curves: Draw slowly for smoother lines
Sharp angles: Draw quickly for more angular shapes
Closed shapes: Return to your starting point to create filled shapes
Open lines: Create arrows or underlines without closing the shape
Once you've drawn a line, you can select it, move it, and adjust its position:
Click directly on any line - selected lines show handles at their endpoints
Select the line, then click and drag to reposition it anywhere on the canvas
Click on empty canvas space to deselect the line
Freehand lines maintain their drawn shape. To resize or reshape a line, you'll need to delete it and draw a new one.
Make your lines visually distinctive by customizing their colors. When a line is selected, the control panel shows color options:
The interior color of closed shapes - great for highlighting regions with semi-transparent colors
The outline/border color of the line - use bright colors for important annotations
Subtle backgrounds: Use light grays and pastels for grouping boxes
Vibrant highlights: Use red, orange, or bright yellow for critical areas
Contrast matters: Ensure colors contrast with nodes and edges
Semi-transparency: Keep opacity moderate so underlying content stays visible
Use lines to group related components visually
Keep line colors subtle to avoid overwhelming the diagram
Draw boundaries around system contexts or deployment zones
Use arrows to indicate flow or importance
Combine with text nodes for clear annotations
Layer lines behind nodes when possible
Drawing boundaries around microservice groups or domains
Highlighting critical path components with colored boxes
Creating visual separators between diagram sections
Annotating legacy vs. new system components
Indicating deployment zones or environments
Marking areas for future implementation
Press Delete key to remove selected line
Press Cmd/Ctrl + Z to undo line drawing
Side navigation (left sidebar) - Enables freehand line drawing mode
Control panel (when line selected) - Changes the interior color of closed shapes
Control panel (when line selected) - Changes the outline color of the line
You've completed all ArkT tutorials! 🎊
✅ Create and connect nodes
✅ Build multi-level diagrams
✅ Use templates for consistency
✅ Add text annotations
✅ Link external resources
✅ Master virtual nodes
✅ Draw custom lines
You're now an ArkT master!
Ready to build amazing diagrams? Here are some recommended next steps:
Combine techniques - The best diagrams use multiple features together (nodes + text + lines + integrations)
Start simple - Begin with basic node diagrams, then add complexity as needed
Save templates - Create templates of your common patterns for reuse
Share knowledge - Document your architecture decisions in your diagrams