How to combine shapes in Illustrator for laser cutting with Ponoko

The right way, and the wrong way

In this short tutorial, I’ll show you how to combine shapes in Illustrator to create single vector objects for laser cutting with Ponoko.

Below is a transcript of the video:

Hi – this is Josh from Ponoko – and today I want to show you how to combine shapes in Illustrator for laser cutting with Ponoko.

To do this, we’ll be using three key menu commands:

  • the first is Object > Group
  • the second is Effect > Pathfinder > Add
  • and the third is Object > Expand Appearance

Before we look at this process in greater detail, lets check out an example of shapes in Illustrator which have been combined incorrectly for laser cutting with Ponoko.

At first glance, this looks perfect for laser cutting. There is a thin blue line which traces around the letters on the top, and a rectangular base on the bottom. However – if we use the Select > All command – you can see that all is not what it seems.

Another way to look at what is really in this file is to use the View > Outline command. This reveals the true vector content of a file – and lets us know what will actually be made. In this case, what it has revealed is that these letters and this rectangle are not truly connected.

What I have done instead is place white fills over the blue lines in my design that I do not want cut out – which unfortunately would not have worked. When it comes to cutting lines and vector engraving lines, the laser cutter will cut or engrave them anywhere they are present in the design – even if they are covered by something else. The white fills I placed over these cutting lines would be ignored, and the lines underneath them would still be cut.

So let’s combine these shapes correctly.

The first thing we do is select all of the shapes we want to combine together. We then use the Object > Group command – which most of you will have used before.

Next is the Effect > Pathfinder > Add command. The Pathfinder effect lets you create new shapes out of overlapping objects – which is exactly what we want.

Finally, we use the Object > Expand Appearance command to turn the pathfinder effect into true vector information. Leaving out this step would be the same as using white fills to cover the lines.

Now when we use the Select > All command, there is nothing highlighted between the pieces we wanted to combine. We can also change to View > Outline, and see that these letters and the rectangle below are truly a single vector object. Once again, this a true representation of what will be laser cut – and this time it’s what we want.

Let’s go through this process one last time. We’ll open a new Ponoko template – and create a collection of overlapping shapes which are formatted for laser cutting with Ponoko…

So now we have something vaguely arty – let’s turn it into a single object for laser cutting. First, we’ll select all the shapes that we’ve laid over each other. Now we use the Object > Group command, the Effect > Pathfinder > Add command, and the Object > Expand Appearance command.

All of these shapes have now been combined into a single object ready for laser cutting with Ponoko. We’ll do a final double check by using the View > Outline command, and it’s definitely correct.

So that’s all there is to it. I hope this technique might be helpful to you in the future – for making new exciting projects with Ponoko.

Thanks!

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8 Responses to “How to combine shapes in Illustrator for laser cutting with Ponoko”

  1. Kristen Turner Says:

    I <3 Illustrator.

  2. Otto Says:

    Excellent tutorial, Josh. As an Illustrator user who is mostly self taught, I found this very helpful. :)

  3. daphne Says:

    Thanks Josh. I have been using various techniques to do that that were much less efficient.

  4. Josh Judkins Says:

    Thanks for the feedback Otto and daphne!

    I plan on creating one how-to piece every two weeks – so if you’ve got things you’re wondering about or tips you think would be great to share, just let us know!

  5. Josh Reuss Says:

    Cool Josh! Wouldn’t hurt to also update tags for “How to Self-Check Your Designs with Illustrator” as well; I was looking for it the other day and only found it under ‘Uncategorized’.

  6. Josh Judkins Says:

    Thanks for the heads-up on that Josh – I’ve just updated the tags and categories now.

  7. Otto Says:

    Will do, Josh. By the way, I just tried your technique on one of my projects. It took me about 15 seconds to accomplish what would have taken me an hour or two to do manually! If you lived near by I would definitely buy you a beer! :)

  8. Josh Judkins Says:

    That’s great to hear, Otto! I’m glad that it’s proving so useful already. =)