One of my biggest struggles has always been items with unusual shapes. Hair brushes, knives, jewelry: getting a pattern to fit those shapes neatly is a nightmare. If I've been struggling with it, I'm guessing you have too.
This is the method I now use to fit a pattern perfectly to any shape. I'm showing it on the xTool F2, but the process is exactly the same on any xTool laser with a camera. You trace the item, offset the outline slightly, lay a pattern over it, then let the software cut the pattern to the shape.
Jump to: Trace the outline · Offset and frame · Add your pattern · Fit the pattern to the shape · Settings and result
Set up the item
Start a new project and take a camera picture of your item in place. My knife is held fairly centrally by my jig. I picked a knife on purpose because it's a tricky shape, with lots of curves and some cutouts, so you have to be fine and precise.
Then set your material. For this one I chose a standard xTool material for black coated aluminum, which behaves in a similar way.
1. Trace the outline with the vector pen
First decide which part of the item you actually want to engrave. I only wanted the black coated part of the blade. I didn't want the sharpened edge, and I wanted to go around the cutouts.
Open the vector pen tool from the vector shapes on the left (or press P on your keyboard), then:
- Start at a clear point, like the tip, and left click. A single click gives you a straight line.
- For a curve, click the next point and hold the left mouse button, then drag. You can bend the line to follow the edge.
- Zoom in and keep going, click and drag, matching the edge as closely as you can. It doesn't have to be perfect, just close. Zoomed in, small wobbles look far worse than they really are.
- If the pen keeps adding a curve when you don't want one, right click and choose Done. Then double click the line to go back in, select the end point and carry on.
- Work your way all the way around until you get back to the start.
The more effort you put in here, the better the result.
Once it's closed, you can set it to Engrave to get a quick idea of whether you've got the shape right.
2. Offset it slightly, then frame
To be extra safe, I shrink the outline a touch so it stays inside the area I want and never marks the surface around it.
- Select the shape and click Offset in the top toolbar.
- Select Inner and untick External.
- Set a small distance. I used 0.1 mm (0.2 mm is fine if you want more margin).
- Click Confirm. You'll now have two shapes, so select the old one and delete it.
Before you do any design work, click Framing and check the outline sits where you want it. The camera isn't directly above the item, so things can be slightly off. One of my shapes was a little low, so I nudged it with the arrow keys until it was right. When you're happy, select all your outline shapes and group them.
3. Add your pattern
Now import the pattern you want. I used a Japanese style triangle pattern SVG. Size it so it looks good on your item. Think about how the pattern will sit on the shape: on a narrow blade, it's nice to have full triangles rather than lots of little bits.
- Give the pattern its own color (I used blue) so it's easy to select.
- Copy and paste it, and join the copies edge to edge. Good pattern files line up neatly.
- Keep stacking copies until the pattern covers the whole area you traced.
- Select all of the pattern and group it.
- Move it around until it looks right. I lined up a full triangle near the tip.
4. Fit the pattern to the shape
This is where the magic happens. I have to say, this was taught to me by viewers on one of my recent live streams, so thank you. I'm just passing it on.
- Make sure your traced outline (underneath) is set to Engrave.
- Now the critical bit, and where I'd been going wrong for a long time: the pattern must be on top. Right click the pattern, go to Arrange and choose Bring to front. It won't work otherwise.
- Drag a box around absolutely everything.
- In the top toolbar, open the Combine dropdown and choose Subtract.
And there it is. It keeps the pattern, but only inside the outline of the knife, and it even worked around the cutouts. Frame it once more to check.
5. Settings and the result
For the engraving, I switched the material to xTool's 1/64" (0.2 mm) Black Coated Aluminum Alloy preset, which has an infrared reference setting. On the F2 I then used:
| Setting | Value |
|---|---|
| Laser | Infrared |
| Power | 100% |
| Speed | 1,750 mm/s |
| Passes | 1 |
| Lines per cm | 200 |
The estimated time was just 16 seconds. Your item will be different, so treat these as a starting point and test first. My free Laser Settings Library and the xTool F2 settings page have lots more.
The finished knife. The triangles are really clear, and the pattern follows the contours of the blade exactly as designed.
You can use exactly the same technique on all sorts of shapes, like hair brushes, on any of the F-series machines. You don't even need a camera, it's just a bit more manual. If you want something to hold odd shapes in the middle of the bed, my self-centering jigs are in the F1 and F2 jigs.
Practice makes it easy
The vector pen takes a little practice, but it's worth it. Keep at it and you'll be fitting patterns to all sorts of things. If you try it, let me know how it went in the comments on the video. And if your problem is a curved or bumpy surface rather than an odd outline, have a look at my guide to curved surface mode.
