Proof grade not cutting through

Every so often, my proof grade material will not cut all the way through. It seems as if there are small knots in the middle plywood layers that the laser takes longer to cut through. I usually saw through the uncut areas with a razor blade, but sometimes it’s too much uncut material and the whole piece is wasted. Is anyone else having these issues? What can I do about it? If this is common for proof grade, I don’t know if it’s worth the premium - I thought proofgrade should be guaranteed to be without issues.



After sawing through with a razor blade

It’s not knots, but an occasional air pocket, a manufacturing defect. When you run across it, notify support and show photos of the edges of the sheet, it should be visible there as well. (They do want to know about it.)


Also, if you haven’t moved the material on the bed, you can run the cut again to get it to go the rest of the way.


This will not work because the issue cannot be seen from the top. I need to lift the material up first to see if it cut all the way through.

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Hold the outer piece in place and lift the pieces with tape. If you can’t lift them, leave them there and re-cut. It’s a habit we all get into after we’ve been lasering for a while – saves a lot of grief. :slight_smile:


What G2N said. You get used to it.

What I have started doing is elevating my material slightly, so the cut parts drop out. I don’t even have to open the lid to ensure all the cuts have gone thru.


If this is that common, then is it really worth the extra money to buy Proofgrade?

You haven’t used anything else, so don’t know yet. I’ve seen this happen on Proofgrade materials on exactly two boards in 3 years of using the machine. The cheap stuff I buy from Home Depot it happens every time, and in a lot more places on each board.

It’s all relative, but try some of the other stuff for yourself to see.


PG materials are almost flawless when used on a clean machine. My comment about elevating the material was in regards to non-PG materials.

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I’ll try cleaning my machine to see if that makes a difference.

I’ve only seen this issue (though frequently) on thick 1/4" Proofgrade plywood so far.

It’s not common. AND Glowforge guarantees PG, so when it happens you can get your material replaced.


Thanks for the tip. I’ll have to start taking more pictures when this happens next time…

I honestly have never had a failure to cut through and I’ve had my Glowforge just about as long as anybody. There are a lot of posts here on the topic and I’ve often wondered why. Maybe luck, maybe some change in newer machines or newer batches of PG, maybe it’s just observation bias because nobody comes here to post every time their proofgrade cuts through perfectly.

Whether it’s worth the extra money depends on what you’re doing with it. Mine is purely a hobby machine, so I’m happy to buy a lot of Proofgrade draftboard (cheap!) for experiments and a little bit of Proofgrade plywood (yowza!) because I have never painted anything in my life and I don’t know how to make a piece of unfinished wood look nice. If I were making and selling things, I’d have to run it all through a spreadsheet. Maybe I could increase my profits with cheaper wood but maybe it would eat up more time and failures.


This just happened to me yesterday on my first attempt to cut a piece of 1/4" PG plywood. I was having all sorts of issue cutting through non-PG 1/4" materials, so I decided to try the 1/4" PG. I even cleaned the machine first to make sure I didn’t have an issue unrelated to the materials. It failed to cut through several areas cleanly. The wood (and money) is wasted.

Perhaps this issue is more prevalent with 1/4” Proofgrade.

As PG is guaranteed to work as long as you’re using PG settings on it, it’s not a waste of money - ask for a replacement piece. That’s the point of PG - it’s literally guaranteed to work!

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Unfortunately I’ve already discarded the pieces that have failed to cut all the way through. I assume Support would require photos as proof.

Yeah, they do. If you run into problems with another sheet, just take a few photos and let them know. In the past they have issued a credit for a manufacturing defect. (Not sure if they still do, but they might still have that policy.)

@Jules is absolutely correct - Proofgrade materials are guaranteed, and we seriously appreciate reports like yours. I’m sorry your print didn’t turn out because of the defect in that sheet, and I’ll be more than happy to send you a gift card to cover a replacement.

Since this has to do with your personal account, we will follow up with you through email. I’m going to close this topic.