Cloudy glass on print head

I noticed this last week but just got around to taking a picture to post it:

That cloudiness in the left window seems permanent. I don’t know if it’s always been there (only got my GF Pro last month) or not, but it’s been there at least the past week. It’s on the inside, and taking a Zeiss wipe to it does nothing. And it doesn’t seem to be related to humidity or anything, my GF is indoors in an air conditioned room and I don’t keep the vent hose hooked up to anything when not in use, so the machine is not exposed to the outside air.

Everything works 100% fine right now, including “set focus” / auto focus. All other glass including the lens looks perfect, so I don’t think it’s related to any material I cut, which is mostly just PG draftboard/wood/acrylic.

Just wondering what’s going on here? Anyone seen this before?

Can’t say if it’d cause you a problem or not. I hope it’s fine!

But I can tell you I can’t look at this picture anymore because my OCD is in overdrive begging me to disassemble the head just to clean that off.


Thanks for letting us know about this. This shouldn’t affect the normal operation of your Glowforge, and it’s good to hear that everything is working properly. However, if you have any trouble using Set Focus, please start a new thread or reach out to us at