Why does my DXF have open contours or “open entities”?
Updated Nov 11, 2026
Short answer: The outline is made of separate lines and arcs with tiny gaps between them. Join them into one closed outline before cutting or ordering.
Check your file now (free)
What do you cut with?
Drop your SVG or DXF file here
or
Free. Nothing is uploaded: the check runs on your own computer.
Marks: open ends cut twice dots and tiny bits text and pictures
Size
Download
More settings
Changing these checks the file again.
Why it happens
A plasma table or a metal shop's laser needs every part outline to be one closed loop. A DXF often breaks that rule without showing it:
- Loose lines and arcs. The outline is saved as many separate pieces that touch end to end but are not joined.
- Tiny gaps at corners, often from snapping turned off, or from a file converted from another format.
- A line drawn twice, which leaves an extra loose piece lying on the outline.
SheetCAM shows these as open paths, other CAM software won't make a toolpath, and online metal shops ask you to fix the file.
How to fix it
- Choose "Plasma or metal shop" and drop your DXF into the checker above. Open ends are marked in red.
- Press "Fix everything I can". Loose pieces are joined into closed outlines, small gaps are closed, and doubled lines and stray points are removed.
- Check the size, then download the DXF in inches or millimeters. It is saved as R12 with the units written in, plain polylines and circles.
By hand: in most CAD programs, select the outline and use Join (or PEDIT › Join in AutoCAD-style programs). If it will not join, there is a gap: zoom in on each corner.
Real example: before and after
What the checker found
- 9 open shapes
- Doubled lines: 1 shape is drawn twice
- 1 stray dot
- Size: 152 mm (6.00 in) wide × 102 mm (4.00 in) tall
What was fixed
- Removed 1 shape that was drawn twice.
- Joined 8 broken pieces into 1 whole shape.
- Closed 1 shape whose ends nearly met.
- Removed 1 stray dot.
Download: before (DXF) · after (DXF)
Questions
What does "open entities" or "open contour" mean?
It means a cut outline does not close: somewhere the line stops instead of meeting its start. Metal-cutting software cannot tell the inside of the part from the outside, so it will not make a toolpath, and online metal shops send the file back.
My DXF looks fine in my CAD program. Why is it open?
Corners can hide gaps of a thousandth of an inch. And many programs save an outline as separate lines and arcs that only touch at their ends. Most CAM software needs them joined, or within a small tolerance.
Can the checker close a big gap?
No. It joins and closes gaps up to 0.5 mm (you can raise this to 5 mm under More settings). A bigger gap usually means part of the outline is missing, which only you can redraw.
Does FireControl read DXF files?
No. Langmuir says FireControl loads G-code. You turn the DXF into G-code in SheetCAM or Fusion first. A clean, closed DXF makes that step work.
Sources
Related answers
- What is an open path, and how do I fix "filled shape is open"?
- Why is my DXF 25.4 times too big or too small?
- Why does my DXF not work in SheetCAM or plasma software, and which DXF version should I save?
- How do I convert an SVG to a DXF for plasma cutting or a metal shop?
- What should I check in a DXF before plasma cutting or ordering metal parts?