How to laser cut cardstock: settings, tips, and avoiding burnt edges

I ran my first cardstock job with the same settings I used for 3mm basswood. Power too high, speed too slow, and I walked away with a pile of brown-edged rectangles that smelled like a campfire. Took about four ruined sheets to figure out what I was doing wrong.

Paper and cardstock cut well on almost any laser. They're cheap, they're fast, and the machine doesn't have to work hard. But get the settings wrong and you'll know immediately. The margin between a clean cut and a scorched edge is a lot thinner than most people expect coming from wood or acrylic.

Why cardstock burns so easily

Wood needs a lot of heat to vaporize. Paper ignites. Those are genuinely different problems. When you're cutting wood you need the beam to dwell long enough to push through the material. With paper, dwelling is exactly what you don't want. The moment the beam sits in one spot a fraction too long the heat spreads sideways through the sheet and the edges turn brown.

This is why paper settings feel wrong when you first look at them. On most materials you increase power to get through them. With cardstock, power isn't usually the issue. Speed is. The beam needs to be moving fast enough that it cuts the fibers cleanly before the surrounding material has time to react.

The golden rule: fast and light

For a 40W CO2 laser, cutting 80gsm copy paper typically runs at 100 to 130 mm/s at 9 to 12% power. For 300gsm cardstock you'll need a bit more, roughly 15 to 20%, but the speed stays high. On a 20W diode laser, copy paper cuts at 7,000 to 10,000 mm/min at 20 to 30% power. Not typos. The power really is that low.

If you're used to cutting wood or acrylic it feels like you're barely doing anything. That's the right feeling. Give paper too much and it burns.

Turn air assist off

Air assist is almost always helpful. Not for paper. On most materials it clears smoke and keeps the lens clean. On lightweight paper, it lifts the sheet off the bed while the laser is still moving across it. Even a small shift ruins the cut line on anything detailed.

Start with air assist off for copy paper and light cardstock. For heavier card, 250gsm and up, a very low setting can help clear residue on dense intricate work. But off is the right default and only worth changing if you're seeing a specific problem.

Keeping the sheet flat

Paper moves. The heat from the laser alone can cause a sheet to warp slightly mid-job, especially on longer runs. A honeycomb bed helps because it supports the material without trapping heat underneath. If you're cutting many small pieces out of one sheet, the finished pieces fall through the honeycomb as they're cut free rather than shifting into the path of the next cut.

Tape the corners down, or use hold-down pins if you have them. On detailed designs with lots of interior cuts, do the inside pieces first and leave the outer border until last. The sheet is much more stable when its perimeter is still intact.

Settings by weight

160gsm cuts noticeably easier than 300gsm. The gap in settings is real and worth knowing before you start. Here's a starting point for a 40W CO2 laser.

80gsm copy paper: 100 to 130 mm/s, 9 to 12% power, 1 pass. 160gsm cardstock: 80 to 100 mm/s, 15 to 18% power, 1 pass. 300gsm heavy cardstock: 65 to 85 mm/s, 18 to 25% power, 1 pass. These are starting points. Your machine, lens condition, and the specific brand of cardstock will all move the numbers around a bit.

Intricate cuts

Cardstock is actually great for detailed cutting work. Paper cut art, greeting cards with fine windows, decorative gift boxes. The laser holds detail that scissors or a craft knife can't, because the kerf is consistent and doesn't push the material at all.

For fine detail work, drop your speed by about 10 to 15% and reduce power by the same amount. It sounds counterintuitive but a slightly slower, lighter pass gives cleaner edges on thin lines. More control. Test on a scrap corner first.

Get your focus right

A beam that's slightly out of focus spreads heat over a wider area. On wood you might not notice. On paper you will. Focus to the top surface of the material. On a honeycomb bed that means focusing to the paper itself, not the honeycomb. A millimeter or two of error that barely affects plywood will cause visible char on a cardstock job.

One pass is enough

If one pass isn't getting through cleanly, adding a second pass at the same settings usually makes things worse rather than better. Two passes chars the edges even when the first one almost cut through. Slow down a little, or add a small amount of power, and try again on a single pass. Paper cuts through in one pass on any properly set up machine.

The settings database on this site has community-tested numbers for cardstock and copy paper across 16 machines. If you're getting consistent char and can't figure out why, it's worth looking at what people running the same machine have found. Sometimes it's a machine-specific quirk rather than anything you're doing wrong.