If you own or have access to a laser cutting machine, stencils can be a quick and easy product to design and laser cut. I’ve been cutting and designing stencils for some time, with my online store containing over 100 stencil products. So, here’s my solution on how to laser cut a stencil.
How to Laser Cut Stencils? Depending on your application, decide which material to laser cut. My go to material is Mylar, but for low cost and single use, you can use paper or card. Design the vector artwork, using stencil fonts for text and numbers, ensuring graphics have sufficient tags to hold internal cut-outs in place. Laser cut on a pin bed to minimise laser flashback.
That’s the basics, but as always with laser cutting, there are a few tricks to getting the optimum settings and consistent results. Read on for more information and tips to make the job easier for you. If you don’t have access to a laser machine and are based in the UK, check out out our Custom Stencil Options in our online store and order what you need there.
What is a Laser Cut Stencil?
A stencil is basically a thin sheet of card, plastic, or metal with a pattern or characters cut out of it. It is used to reproduce the cut-out design onto a suitable surface, by the application of ink or paint through the holes in the design. Paper and card stencils are typically single use stencils, and can even be manually cut.
A laser cut stencil is, simply put, a stencil that has been cut with a laser. Laser cutting offers the benefits of fast turn around, intricate detail, precision and repeatability.
Here at LaserUser.com, we prefer to use Mylar polyester film due to its durability, chemical resistance and longevity. But, as mentioned, most semi-rigid and rigid materials such as paper, card, plastics, mdf and wood can be used.
You can make stencils from thin metal, but we do not have that capability at LaserUser.
The process is very similar for whatever material you use, but the laser settings will of course be different. Here. you can check what materials a laser cutter can cut.
What is Mylar
MYLAR® polyester film is a flexible, strong and durable film with an unusual balance of properties making it suitable for many industrial applications. Type MYLAR® A is a tough general purpose film available in 12µm to 500µm thickness range.
In film thicknesses190µm and above, MYLAR® is hazy, has a tensile strength that averages 210 MPa, has excellent resistance to moisture and most chemicals and can withstand temperature extremes from -70°C to 150°C. Because it contains no plasticisers MYLAR® A does not become brittle with age under normal conditions.
Mylar is easy to clean, solvent resistant and durable. Making it the ideal material for multiuse stencils. We typically offer 190, 250 and 350 micron Mylar.
I purchase my Mylar in roll format from UK Insulations.
Is Mylar Food Safe?
FDA Food Contact Status – All gauges of Mylar® A comply with the Food and Drug Administration regulation 21 CFR 177.1630 — Polyethylene phthalate polymers.
This regulation describes films which may be safely used in contact with all types of food excluding alcoholic beverages. Uncoated films such as Mylar® A can be used to contain foods during oven cooking or oven baking at temperatures above 250 °F.
So it can be used for cake stencils and coffee stencils for example.
How to Laser Cut Mylar Stencils
As mentioned previously, I tend to use 190, 250 and 350 micron Mylar. In thin sheets, mylar cuts well, but can be a little smelly and generates a lot of smoke, so good ventilation is needed. If the stencil is being used for food purposes, it’s best to have good airflow across the top and bottom surfaces. This removes all smoke and particulates before they have a chance to stick to the surface. Of course, the Mylar will need to be washed before use.
I prefer to cut on a pin bed as it allows me to use magnets at the edges to keep the material flat. Waste material will usually fall free and there is minimal risk of flashback to damage the rear of the material.
Video of 250 micron Mylar being laser cut
I use the following settings:
- 190 micron Mylar: Speed 30mm/s | Max Power 11% | Min Power 10% (Approx. 8 Watts)
- 250 micron Mylar: Speed 30mm/s | Max Power 11.5% | Min Power 10% (Approx. 9 Watts)
- 350 micron Mylar: Speed 30mm/s | Max Power 12% | Min Power 10% (Approx. 10 Watts)
The power settings for all three thicknesses of Mylar are well within the pre-ionisation zone of the laser, and utilises the zones high frequency characteristics to give minimal charring or burning of the material. You will of course need to carry out your own material tests to determine the settings for your particular machine.
Text Based Stencils
These are pretty straightforward, unless you need to use a specific font. Otherwise, you just choose the most suitable Stencil Font you have available. The PDF document below shows a range of stencil fonts available, a quick search of Google will reveal 100’s more.
If you need to use a specific font, E.g. for corporate / branding reasons. You will need to manually doctor the artwork to place tags to stop central portions from falling out. The tags can then be painted out once the stencil has dried.
Both RDWorks and Lightburn have the capabilities to add tags to text artwork, although the process is easier in Lightburn. Alternatively, you could use a vector drawing package such as Inkscape to do the same thing and import the finished file into your Laser software package of choice.
In the image above, taken from Lightburn, you can see the stages in converting a font to make it suitable for stencilling;
- Original Font Character – Converted to path
- Using Edit Nodes – one side of the A has been tagged
- Using Edit Nodes – two sides of the A have been tagged
- Selecting the whole tagged character A – use Auto-join selected Shapes to close the shapes
- Character is changed to a fill layer which shows as a coloured shape.
Graphic Based Stencils
Graphic based stencils tend to more difficult to generate as it is not as easy to spot areas where central portions may fall out. This becomes far more difficult for complex graphics or geometric shapes. One trick I use is to temporarily change the layer mode from cut to fill and view the whole image in the job viewer. This makes it easier to spot errors and will also pick up any shapes that are not closed.
Conclusion to Laser Cut Stencils
Stencils can be both simple and complex, but the process to design and laser cut is the same whatever material you decide to use. Using the stencils will be covered in another post, but it is possible to use low tack spray adhesive on the back of the stencil to keep it in place during the painting / spraying process.
Alternative To Using a Laser Cut Stencil?
If you don’t fancy the effort and potential mess of painting / spraying a stencil and the time taken for it to dry. You could always consider using a self adhesive Cut Vinyl Decal Instead