laser cut

Laser Cutting Kerf

When the laser cuts through material it burns away a small amount of that material - this is called the laser cutting kerf. The amount of kerf is dependent on the material type and thickness, along with a couple other variables (including the lens on that particular laser cutter, air pressure, etc). Typically the kerf ranges from about .15mm to .2mm.

 
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To account for the laser cutting kerf, we offset the cut paths by the amount of the cutting kerf. Most of the time, we do this in our laser cutting software, but this can also be done in other CAD based programs (Illustrator, Sketchup, etc.)

It isn’t always necessary to offset cut paths to account for the kerf if something doesn’t need to be an exact fit. For example, if we’re cutting out a wooden 5” x 7” menu card, accounting for the offset isn’t necessary, as the piece will be just barely smaller than 5”x7” - measuring .49940” x .699040”.

One example of a project where accounting for the kerf IS NECESSARY is when we’re doing inlay. If we’re cutting an acrylic piece that a wooden letter will fit into, we need to account for the kerf to ensure that everything is a tight fit. If the kerf isn’t accounted for, the two pieces will not fit together.

 
Laser Cut Wood and Acrylic Inlay
 

Good Files Make the Magic Happen - Illustrator Artboards

Illustrator is a vector based drawing program that can be used to create vector paths for laser cutting. Many of our clients use Illustrator because it’s one of the easiest programs to use, especially for your beginners!

Illustrator artboards are the background in which you create your design on. It’s kind of like a canvas for a painter…you can make it a variety of sizes and have more than 1 for your artwork.

To create an artboard, open Illustrator and select File - New. A New Document menu will pop up. This is where you can select all of the details for the artboard, like the size, orientation, and the quantity.

I always start off by naming my file. Once you’ve named your file, you can select the number of artboards you’d like. If you’d like more than 1, the greyed out menu options will pop up and you’ll be able to change more info about the artboard.

Laser Cutting File Prep Tutorial for Adobe Illustrator.

I typically like to have more than 1 artboard if I’m working on a piece that has a front and back side or if I’m working on several pieces that are very similar. For example, a menu that has a front and back or a set of coasters that will vary in design. Once you’ve titled your piece, you can select the profile, these include options for if you’re using the final piece for the web, print, etc. I normally stick with custom.

Artboard tutorial for Illustrator for Laser Cut Co in Houston.

The following steps will determine the number, the spacing, the layout and the size of your art boards. If you select more than 1 artboard, the greyed out menu area will become active and you can select the layout of these using the 5 boxes next to the number of art boards. Depending on what you’re making, you might want a column of artboards vs. a row of artboards - this is pretty much just personal preference.

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The next option you have is spacing. I typically like my artboards to be spaced .5” away from each other, but again, this is just personal preference.

The next option is the size. You can select from a number of presets or you can leave it on custom and set your own. The units box on the right hand side of the screen will allow you to change to a variety of units including inches, centimeters, pixels, points, etc.

I typically work in inches or centimeters because we’re making physical objects, so it’s nice to be able to work directly in the size that we’ll be cutting in.

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There is also an option to change the orientation - both vertical and horizontal. Once this is set, click OK and your art boards will appear!

If you want to add or delete an artboard once you’ve started designing, you can use the artboards tool to do so.

Illustrator Artboard for laser cutting file prep.

Once you select this, your layout will change slightly and an artboard tool bar will appear at the top of your workspace. If you select the little page with a corner flipped, this will allow you to add a new artboard. This artboard can be placed anywhere on your grey workspace.

Adobe Illustrator Artboard Tutorial for Laser Cutting.

When you’re finished with your design, you can also choose if you’d like to save all artboards or only selected ones. If you select File - Save - OK, you’ll get to a second save menu. Under Options, you’ll see a checkbox to save each artboard as a separate file, or to just a save a range of art boards.

How to save selected dartboards in Adobe Illustrator

To Mask or Not To Mask

We love mask in our shop! Masking material provides a protective layer on the surface of material during cutting and engraving that helps prevent burn marks. Masking paper is pretty comparable to masking tape. We use a low tack paper mask that can be easily removed and doesn’t leave a tacky residue.

We use 24” mask that’s on a roll, which allows us to mask large surfaces fairly quickly. When we’re putting on the mask, we attempt to avoid having creases or air bubbles underneath the mask, as this can allow for burn marks. We use a rubber squeegee to press the mask firmly all over the surface. We typically mask wood, leather, mat board, and paper.

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When we purchase acrylic, it arrives with a protective mask already on it. Sometimes it’s a paper mask and sometimes it’s a thin plastic mask. We typically try to get acrylic with the paper mask, as it’s much easier to remove.

Laser Cut Acrylic with arch pattern
Laser Cut Acrylic Pattern with Mask Being Removed.

If material is left un-masked during cutting/engraving, there will be small burn marks around these areas. Sometime this is a wanted aesthetic, but most of the time, this halo effect is unwanted.

Sometimes there are small areas where the mask wasn’t fully pressed down against the surface and there are slight burn marks in these areas. To solve this issue with wood, we’re able to gently sand the area down. To solve this issue with mat board, we’re able to clean the surface with a barely damp paper towel. For other materials, like acrylic, leather, or paper, there’s not a good way to reverse the burned effect.

When you’re placing an order, we will confirm with you if we’ll remove the mask or if we will deliver your pieces with the mask on. For most acrylic pieces, we will deliver the pieces with the mask on to help protect the surfaces until you’re ready to install or use the piece. This is especially important with mirrored pieces, as the mirrored acrylic easily picks up finger prints. Also, some materials can be pretty time consuming to de-mask. If your pieces have a complex engraved design, it might take a few minutes to de-mask per piece. For complex pieces, we’ll give you an estimate that includes cost if we remove the mask or if we deliver the pieces with the mask on.

Laser Cut Pieces of Material - MDF, Bamboo Plywood, Birch Plywood and Leather with protective masking