Cardboard cutting (solved)

Thankyou guys for the assistance! and a special thanks to @geek2nurse! it became obvious after all of the comments that the main issue was that I wasnt playing with the speed, and now Ive completed my first rough… ROUGH draft. the speed and amount of responses was amazing and I want to thank you all! 20180725_195843|375x500

hey guys thanks for clicking. unfortunately i have the skills of a potato. I’ve seen people post here before about cutting cardboard but their solutions don’t seem to work for me.

the main issue is, I cant seem to get a clean cut through the bottom end of the corrugated cardboard.

I set the height to 0.15" (even though the actual is more like 0.11) and I’ve tried power levels from 40 progressing to 75.

Even so, it will only cut completely through on the more particular regions of the design.

Any help would be greatly appreciated!!


Technically because the beam diverges slightly away from the focus point. There would be less power the further above the material the focus was set. It may not have a great effect, but if you tried somewhere between 0.05" to 0.11" the maximum power would be on or within the material.

Cutting a new material is as much an art as a science. Experimenting with lowering the speed and raising the power enough to cut through, but not char or cause excessive flames is required. And of course ensuring that everything is perfectly flat by holding it down with magnets, weights or pins is important for all materials.

Someone else may help with the specific cardboard settings. I never use it.


Like @rpegg said, you want to use the actual thickness of the material for cutting, not a point somewhere above the surface. That’s probably why it’s not cutting through in this case.

Couple of other important points with cutting cardboard:

You need to make sure you always watch corrugated cardboard when you cut it…the chambers in the cardboard hold air that feed the flame and you can start a fire with the wrong settings, or if the cardboard shifts. Make sure you pin it down before you cut and have it perfectly flat.

All settings for materials not supplied by Glowforge can be easily searched in the Beyond the Manual Category by using the material name and the word “settings”. (And if there aren’t any settings for a particular material, it’s probably not safe to cut it.) :smile:


For cardboard closer to 0.25" thick I use a power of 90 and a speed of 180 to 220 depending on how much char is acceptable (the slower the more char.) At the faster speeds the bottom may be perforated instead of completely cut through, but I don’t leave what looks like fingerprint powder all over everything either.


this sounds to me like your cardboard isn’t flat. any material that isn’t perfectly flat on the bed can easily have issues where it cuts through in some places and not in others. you can use magnets to hold the cardboard down flat.


Seconding everything @Jules said. Use the actual height, and have a fire extinguisher on hand.

I use speed 250, power 100 (not full) with my 45 watt GF Pro. My database I’ve collected over the years has 40% speed with 100% power for 40watt lasers which translates to 200 speed, 100 power.


I use lots of magnets to hold down cardboard – it doesn’t lie flat on its own (“almost” isn’t good enough!). Place magnets, check screen preview to make sure they aren’t too close to any cut lines, adjust as necessary before starting the job.

The last box I cut up to use measured 0.12" thick.

Don’t set the focus higher than it really is, or the GF thinks the surface of the material is above the actual surface and you end up with a defocused beam that won’t cut all the way through. That can be good when engraving and trying to blur the engrave to eliminate lines, but not so good for getting a clean cut.

My settings for cutting cardboard (stolen from my brother @timjedwards, who did all the grunt work, because hey, that’s why God made little brothers, right???) are 170 speed and 60 power (I have the Basic model, but Tim’s is a Pro). I haven’t had flames with that as long as I don’t try to do something with lots of cuts close together, like a living hinge.

Here’s a cardboard prototype / preview of my current project, which will end up in Free Designs once I get it perfected:


Good luck!


@rpegg well, pegged it.

Corrugated pasteboard is probably the hardiest thing I’ve cut to get good consistent cuts on. You have to over power just a bit to get though the hard to cut spots but not so much as to burn everything up. I looked and all my notes are too old to be useful. So start with those @Jules said but realize that you still might have to experiment.


the other thing to remember is that, unless you’re buying full sheets from a vendor, cutting up boxes means your thickness is going to be variable (i.e., measure every time) and that sometimes your settings will need to be tweaked to account for the different thicknesses and composition. some cardboard is made up of denser material than others.


For those that might not know, the speed and power settings are designed to be the same for all speeds, and for power between 0-100 for both Basic and Pro. Full power (higher than 100) is different for the Basic and Pro.


I have saved way too many boxes expecting to use them for experiment and shipping as smaller boxes or securing pieces against breakages, but as yet I have not shipped anything and I have been too chicken to experiment a lot as I have had enough flame issues with the woods.

A question I have not tried but wondering if others have is to run a wet cloth over the cardboard making it slightly damp before cutting as the laser will quickly wipe away the dampness where it is cutting but it would retard flames where the laser has not been. This is only an untested idea for cardboard and with wood trying to cut through 1\2" material there were very mixed results as the blower shoving flames to the front also dried out and charred the wood down wind anyway.


The only time I had a cardboard fire is the very first day I had the glowforge last August. I was trying to figure out how to do something and wound up engraving a thick line I wanted to cut. The engrave kept the beam in basically the same area so long an ember blew between layers of the cardboard and started a fire. A damp wash cloth extinguished the fire. Having just burned about a wheelie bin worth of cardboard Monday night (the city refuses to pick up the recyclables often enough and cardboard takes up lots of room) I can attest that there is plenty of potential thermal energy in it. But if you’re watching, you should be at the damp-cloth-level-of-fire-protection if things go south. That said, I do keep a 5lb fire extinguisher around the door in order to save the house.

I also ignited parchment paper (kind of ironic don’t ya think?) when a circle of it blew through the laser beam. My hand did the trick there.


I used a speed of 500 and full power to cut out a bunch of animal shapes for a birthday party from box cardboard. It worked great for me.

The teenage sister of our babysitter hand painted them all.


It’s the inner stuff that I’ve had the most trouble with catching fire.

Dead flat with a steel strip and strong magnets.

I do 260 zooms and 80 pews with a .150" thickness. That is pretty reliable.

Avoid tight radii and cuts closer than 1/8" and you should be fine. But keep an eye on it.


I dunno what it is, but I think I want one!


^^^ ditto


When I was building architectural models in foam core I figured out that with one cut that went through the first layer and the foam and scored the back layer and then a second cut that matched the thickness of the foam core away but only cut the first layer and foam then the strip of first layer and foam taken off would not only create a very nice 90° corner but with hot glue it was fast and very strong. So much so the shop owner was able to work so much faster that I was no longer needed and got fired :frowning:

It would be very interesting if the Glowforge could accomplish that task to make small boxes from big ones.
The parallel cuts would be needed but fast enough to not cut all the way through.


I’ll keep this in mind when I want more robust prototype thankyou!

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thats so cool! i wa too chicken to go full power though haha. perhaps I’ll give it a shot

I like that this is one of the faster speeds I’ve seen and the wet cloth sounds very viable! its apparent to me I still have some testing ahead of me for the best speed and results!