This is a continuation of my other Instructables, How to Make Halftone Vectors for Lasercutting (Method 1). As the title suggests, this is Method 2! They produce different results, so it's up to you to choose which one you prefer appearance-wise. Both methods are done in Adobe Illustrator. As mentioned in my other Instructable, "halftone" refers to an art style meant to simulate continuous tone imagery through the use of dots, similar to stippling; it's often used in comics and has its own unique look (read more here).
Step 1: Choose Your File + Onto Illustrator!
Import the image you'd like to use into Illustrator; I will continue to use my lion's head so as to clearly indicate the difference between the two Halftone methods and how they turn out when lasercut. Create a new Illustrator file, and place your image into it (File -> Place). You'll want to Embed the image, so that Illustrator can apply more methods to it.
Step 2: Object Mosaic
This time, instead of using the Color Halftone method in Illustrator, we'll be creating an Object Mosaic out of our embedded image. To reach this option, select your image and find the Object -> Create Object Mosaic... option near the top of the window.
Step 3: Dialog Box
You'll get the Create Object Mosaic dialog box, and get to choose your settings! The most relevant one for us will be the Number of Tiles, since our "tiles" will end up creating our halftone circles and you want enough to accurately represent your image. Since my images have been fairly small (within 12" x 12") I have found that keeping the number of tiles within 100 has worked fairly well. Still, I highly recommend you play with these settings based on the complexity of your image! Furthermore, select Use Ratio to create evenly sized and spaced square tiles.
Step 4: Graphic Styles Pt. 1
Now, double click the grouped tile vectors to enter Isolation Mode for the group (you should see an extra gray line indicating that you're in Layer _ <Group>) and then select one tile of a specific color. In our case, since we started with a black and white image, our tiles are grayscale (in shades of black to white); thus, we'll want to select the a Black tile since they are the primary building blocks of our image. Then, with that tile selected, click Effect -> Convert to Shape -> Ellipse... .
Step 5: Graphic Styles Pt. 2
After selecting Ellipse, the Shape Options dialog box should pop up. Set size to Absolute to save later headaches, then adjust the Width and Height of your circle so that it fits within your tile (you don't want the created circle to be larger than the tile, otherwise they will overlap!). Use the Preview option to help you visualize your changes!
Then, you'll want to save your ellipse as a Graphic Style. Go to Window -> Graphic Styles at the top to pull up the Graphic Styles window, and then drag and drop your created ellipse into it. You should see a new Graphic Style pop up that looks like a circle!
Step 6: Magic Wand Tool
After creating your Graphic Style with your black dot, you can use the Magic Wand Tool (shortcut Y for Windows) to select all black tiles in your group. Then, if you select your new Graphic Style from the Graphic Styles window while all tiles are selected, you'll see them change into the style! All your black tiles should now have turned into black circles.
Step 7: Shades
Now you'll want to repeat the above process with your shades of grey! I was a bit lazy this time around, so I decided to change all my shades of grey into one smaller circle; if you'd like to be more careful with your design, feel free to create more circles of various sizes depending on the various shades of color of your original image!
Step 8: Change the Colors
Lastly, you'll want to ExitIsolation Mode, and delete the original image so you can see your circles. It should look like a halftone image! Then, as before, all that's left is to change their colors appropriately for laser cutting. This will vary across each machine, and since ours take full red vectors as cutting lines, I adjusted the colors to be red. There you go! You now have an awesome design ready for laser cutting. Please let me know if you have any questions, and I'll include my lion2 file for fun in case you want to open it to see how it looks.
Step 9: Lasercut!
Here's a look at how it turned out when lasercut! There's definitely a difference between this method and Method 1, so let me know which one you prefer and why!