You have a few straightforward ways to draw perfectly straight lines in Concepts:

• Line Smoothing (Quick & Easy)
  • Set your tool's Line Smoothing to 100% (tap the squiggly line icon on your tool wheel).
  • Every stroke you draw will automatically become a straight line.
  • Pro Tip: Draw one line, then duplicate it (select and tap the duplicate button) for fast, parallel lines.

• Line Guide (Precise Control)

  • Access the Line Guide by tapping the Precision menu, then the Guide tab (looks like a ruler).
  • Tap the circle next to the Guide tab to activate it. Position the guide with one finger or rotate/resize with two.
  • Draw anywhere near or on the guide, and your stroke will snap to it.
  • Bonus: Double-tap the crosshairs to constrain the line between its handles, or tap+hold the length value to enter an exact measurement.

• Line Object (Ready-Made)

  • Import a Line Object directly from your Object Library.
  • Drag it onto your canvas, and use the Nudge tool to adjust its length
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For a visual walkthrough, check out our illustrated tutorial.