Mylar sheets- Safe to Use? (Settings)

We have our Glowforge (YAY!) We are interested in making some stencils to use for painting a design on a focal wall in our home. Typically these are made with the semi-opaque Mylar sheets (approx 7mm thick) that are flexible and light. Blank mylar sheets are available to purchase, however, I am not finding anything that is “proof-grade” and I am not sure that the mylar is safe to use in the Glowforge. Anyone know?

There is proof grade acrylic, but this is thicker than is useful for stenciling (unless I am not seeing the right stuff). My spouse suggested masking material (such as comes on the “proof-grade” material), or even buying the blue painters tape that is sold in sheets (often used in 3-D printers). Anyone with knowledge on these items or making stencils with the Glowforge, please respond!

Thanks in advance!

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Congrats on getting your :glowforge:!!

This thread may be exactly what you are looking for:

https://community.glowforge.com/t/silk-screening-with-mylar/13975?u=johnse&source_topic_id=17275

In short, Mylar is fine.

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Try a forum search for Mylar. I know it has come up a few times.

For masking materials this works well:

https://www.amazon.com/gp/product/B017URUT92

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Thanks! I was hoping that it could work. I had done a search for Mylar on here, but I didn’t see this discussion come up, so thanks for the link.

Thanks for the link. It looks like this product is made of paper with a sticky back, and may work for my purposes. I’m not familiar with vinyl transfers or how this kind of sticky paper is used, but will look into it more. One of the reviewers indicated that they used this with their laser (unknown brand) as a masker product for wood to help prevent burn marks.

I use it with the GF to mask Baltic Birch or MDF I get locally. Very similar to the masking used on PG materials.

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That’s how I use it. I’ve been applying the paper tape to leather before cutting in the GF. It keeps the smoke stains off the finished surface for a quicker cleanup before dyeing.

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Some time ago I made a couple of posts in a sticker thread about using transfer tape, here and here.

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Oh, anmd in my limited experience, you need to apply some kind of masking to mylar because the autofocus errors out otherwise. Don’t know if that’s because of the transparent or because of the shiny.

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I have been using plain shiny mylar without any trouble. Since it is only .003" thick I use a sheet of very much perforated PG plywood under it so I can get a good focus height.

You can also get drawing “vellum” which is really just mylar with a matte surface finish.

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Good to know about using masking with mylar. Thanks for the tip!

Apologies to correct you @jkopel but I think you are thinking of polyester drafting film (aka matte mylar drawing film). If you pick up vellum at the art supply store you’ll get a paper product made of wood pulp and cotton (or calfskin if you’re at a fancy book bindery).

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No worries. To be clear that is why I used the quotes. :slight_smile:
There is very little standardization in terms in the art supply business.

It’s the standard of what the supplies tell you their name. :wink:

Hey, that’s how I choose what to eat. I stare at a menu until the food tells me what I’m getting.

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vellum is a term that gets thrown around loosely to mean a whole lot of different things. it rarely means the same thing to two different people who haven’t had a conversation about it before to clarify.

I’m using 4 mil mylar sheets to make PCB stencils. These are basically letter size ( just a bit smaller) so I put a sheet of 110 lb 8.5 x 11" card stock underneath it and secured them both with magnets. Using a focus height of 0.01" it works perfectly. Since the card stock also acts like a wasteboard, I can tell that the laser power is dialed in perfectly as it cleanly cuts all the way through the mylar but not all the way through the card stock.

My settings:

  • Stencil cutouts: Manual Engrave 650/45
  • Embossed text: Manual Engrave 650/15
  • Stencil cuts: Manual Cut 500/45

Again, material height of 0.01" (lowest setting).

Use the cuts judiciously as it’s pretty easy for the material to fly off the bed once cut.

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Thank you for the settings!

I personally did a stencil cut at : Manual Cut 500/70 and put a 13x19 100lb card stock underneath. I tried the 500/45 and it didn’t work as well and didn’t cut through as well throughout my piece. I also changed the material height to 0.02". It worked perfect and when I peeled off the mylar all the excess stayed stuck to the paper. Speeding up that process as well.
(see example attached)

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Hi Nimbi, I tried cutting 7.5 mils mylar with the same setting but stencil looks dirty with burn effects on it. I see your mylar looks clean and well cut.

Can you help me

Folks, I’m going to shift this to the Beyond the Manual category and tag it with “Settings” since it contains useful information on cutting Mylar. :slightly_smiling_face:

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