Plastic Codes - What is Laserable?

I think we all will be tempted to reuse plastics in our Glowforges… but before we go crazy it might worth checking the Resin Identification Codes (RIC) normally on the bottom.

From my understanding we should OK lasering these codes: 1 - PET, 2 - HDPE, 4 - LDPE, 5 - PP, 6 - PS.

And need to stay away from these codes: 3 - PVC/UPVC/PPCV

Code 7 - Other includes: Acrylic (OK), ABS (Bad), Polyurethane (Bad).

A couple of previous posts linked to this article, but if the plastic has the RIC, then just go with that…


Why is ABS on the bad list? It looks like it can be laser cut but emits hydrogen cyanide gas. Presumably that is not problem with external ventilation?

Does the filter unit get rid of hydrogen cyanide?


Also, what is wrong with laser cutting PU?


ABS melts badly so it’s almost not worth it…
I’ve etched on it but it’s not really clean.


I’m not a chemist, but anything with Cyanide it sounds bad to me… :scream: :skull_crossbones:

Its bad to breath it but I don’t think it damages the machine like HCl does, so I should be able to cut it with external ventilation. I was hoping the filer would cope with it but is sounds like it is only safe with proof grade materials. I really wish the filter had an output port that I could vent outside. Then I could cut anything without any risk of being poisoned myself and only a very small risk to the outside environment. Seems like unless you only use proofgrade the filer is useless, so I will probably cancel mine.

As the other person posted, it’s probably fine if you’re on top of your venting. I’m willing to bet you eat things with -CN everyday. Lots of chemicals sound scary when isolated but are actually okay (free chlorine is pretty heinous but we all love table salt, for example).

1 Like

So we probably shouldn’t make custom-engraved salt-lick blocks for our cows.


Hah! Wouldn’t be able to fit it in your glowforge anyway; most of them are pretty big if I remember correctly.

1 Like

I’m curious how you came to this conclusion? I would think that if the filter works for proofgrade acrylic, maple & oak, it should work equally well for non-proofgrade acrylic, maple and oak.

I would be a bit more concerned with filtering for a material listed as “unsafe” in various other places online (like some of the links in this thread) or material that has no proofgrade equivalent (since that could (but not necessarily) mean there was a safety reason not to supply said material).

Granted, if I had a good way to vent to the outside and didn’t plan on ever taking the glowforge to any locations where external venting would be a problem, I’d have canceled my filter by now.


Well I read somewhere Glowforge only guarantee the output is safe to breath if you use their materials. I don’t think it will be economical to import proof grade to the UK.

Yes I would be happy using non-proof grade woods and acrylic but I am not very interested in natural woods as I am into engineering rather than art. I am more likely to use plywood, MDF or plastics. Then it seems to be a lottery whether they will be safe with a filter or not. I can see that ABS is laser cut commercially but is it safe with a Glowforge filter? What about Derlin, I think that gives of formaldehyde?

Unless Glowforge give a list of materials that are safe (and common ones that are unsafe) with the filter it isn’t practical.

I don’t remember reading that, but it could have slipped past me. Do you remember where you saw that?
I saw that the glowforge warranty would cover any damage to the machine caused by proofgrade materials (which makes sense, as they are formulating those materials themselves and actually have control over what goes into them), and I would imagine that covers the filter too.

I have not seen any specifics of what the filter cannot handle. I did see @dan mention that people should only use laser-approved materials from trusted sources. He recommends Proofgrade, of course, but also mentioned some of the other established names that sell laser-safe materials to the public, such as inventables. Surely there is a similar supplier in the UK? (If not… business op!!)

Considering that people want to put these into schools, hospitals, homes, etc… the filter had better work pretty darn well, or come with some serious warning stickers.

Personally, I would never equate what is done commercially with what is safe… especially in terms of emissions!

You could very well be right about that, which would be a bummer.
On the flip side, maybe there will be a bulk importer and it would be an option.

@palmercr, what is happening is that glowforge is placing a guarantee on their proofgrade materials as well as the Glowforge - 2 separate guarantees. The guarantee for their proof grade is that 1 - it won’t hurt your machine, and 2 - they have verified it is relatively non-toxic (nothing unexpected hidden within the material. That really has little to do with how the filter will work. It will work exactly the same for proofgrade and non proofgrade. It is highly unlikely glowforge will provide any kind of list other than their proofgrade just because of liability. The general lists can be found online fairly easily. With any laser material, just be careful.


Yes I can buy laser grade materials in the UK and would trust the filter to work with them. The problem is I want to be able to laser anything that doesn’t damage the machine.

For example I have some PP chopping board that I want to cut up to make a print surface for my 3D printer. PP should be safe to cut but this is coloured, so who knows what the pigment will produce when vaporised? I can get laser safe PP but not in the thickness I want.

I will probably need to cut it before my Glowforge arrives so I will use my CNC router or perhaps my bandsaw.

hmmm that sounds kinda cool actually… I wonder if you can engrave the Himalayan Salt Blocks used for serving. May have to check into that…


I know these posts were years ago, but have you used PET with the glowforge yet? I have a project and i want to lasercut some of the thin PET clamshell plastic that salad and other food stuff comes in. it would make a nice windshield for toy cars.

People have, yes:

(The first post in that search result has some settings and summary.)

1 Like