Cutting paper / thin card with 50W co2 laser

I am having an issue when cutting white card (160gsm to 240gsm I wanted to use) getting brown edges.

I have seen a few posts on here, but all regarding diode lasers which isn’t really helpful for me as I have a CO2 laser (50W).

I can cut the card easily - and corrugated card works really well, but then you don’t see brown edges on that!

I have upgraded air assist and extraction, and currently cutting on a honeycomb bed (cleaned!)

I saw that dot mode might be helpful, but would appreciate some advice from anyone who has had success, as even with fiddling and trying a variety of settings, I can’t do an acceptable job.


You have a picture?

Try different speeds. I think faster=less smoke…
Try different card brands, formulations.
Some papers burn with more smoke than others.

Also try more than one layer and see if bottom layer comes out cleaner.

Paper isn’t easy. Every weight and brand seems to want a little different setting but I can get a reasonably clean “brown free” cut from my 80w.

In my library notes I have .010" cardstock listed at 180mm/s, 33% power max, 7% min, so those were probably correct for whatever the last paper thing I made…

You just need to experiment a lot. If it’s getting especially dark in the corners then you need less min power.

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Thanks for your suggestions, I converted 0.010" to 25 micron (or normal 80gsm printer paper I think).
I will try a different brand of paper/card to see if that makes a difference.
Ideally the card I wish to cut is 80lb (240gsm) ‘business card’ thickness.

Does anyone use dot mode for this?


0.010" = ~.25 mm, about business card thickness.

I’ve never tried dot mode.
For testing power settings for paper I like cutting little stars. Keep adjusting the “min” power until the points and corners don’t quite cut through anymore then back it up until they just do. Do the same for the straight sides and “max” power to find the lowest setting where the sides still cut.

Thanks for this. I’ve never set max and min to anything other than the same as each other!