Has anyone else had damaged/fog marks left when cutting clear acrylic? I have tried medium and thick clear acrylic, and am using the suggested Glowforge setting for cutting, but every time the acrylic is ruined. I have tried washing with warm water. I have tried an acrylic cleaner. The fog marks do not come off. Help!
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Welcome to the forum.
Cast acrylic is pretty standard stuff and should cut without issue using the appropriate Proofgrade setting.
Is your acrylic masked? Where did you get the acrylic? Have you tried using a thin coat of dish soap (allow to dry thoroughly) as a mask?
Can you share a photo of your fogged acrylic?
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I am having the same trouble. I bought a bunch of different colored acrylic from Amazon. I haven’t used acrylic in a long time so I don’t know if I should remove the clear plastic coating before cutting. Anyway, I did and the cuts did leave a slight burned area on the edges and I am having trouble removing it. Also, I am having trouble engraving these. What should I change the settings to? All help is greatly appreciated.
Mary
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Hi Mary,
The fact that you said your acrylic has a clear plastic masking on it leads me to believe that it’s not cast acrylic but extruded acrylic which does not cut or engrave well at all. I don’t think changing the settings will make a difference. Cast acrylic almost always has a paper masking on it rather than plastic.
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Extruded acrylic cuts beautifully and it engraves fine but without as much contrast. Depending on what you’re using it for that may or may not be an issue.
While plastic masking is more common on extruded acrylic, plastic masking by itself is not an ironclad indicator of cast vs extruded; I’ve seen both types of masking on both types of acrylic.
What we can say is that typically you don’t get burn marks on acrylic of either type. If you are it’s most likely caused by one or more of three major causes:
- Your plastic (or paper) masking and/or a very dirty crumb tray is causing burn residue
- You do not actually have acrylic, polycarbonate and other clear plastics are sometimes marketed as acrylic sheets
- Your settings or design are far out of recommended range and you are actually igniting your acrylic.
If I were in your position I’d focus my effort on isolating each of those three causes and see if it helps you figure out where the issue is coming from.
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I suggest using Proofgrade settings for all cast acrylic. I remove any plastic masking materials but I leave paper masking on. When you say you are having trouble engraving, could you be more specific about the trouble you are having. Is the engrave not deep enough, or lacks contrast or has lines showing? Maybe share a picture of your project so we can see the burned edges and poor engrave.
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It appears that my comments, while not entirely wrong, are off the mark, so I’m glad those more knowledgeable have stepped up with better answers.
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I think your advice was really good — generally paper masking is more common on cast, just not always. Lots of manufacturers out there, can’t always trust them to follow the unspoken rule 
Cast is generally nicer to cut because it is slightly less stinky, but extruded does cut pretty well.
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I used the proofgrade settings and it did not engrave at all.
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Please share a screenshot of your acrylic on the Glowforge bed along with the settings you selected for engraving. Also, which Glowforge do you have? If you were able to cut the acrylic, you will definitely be able to engrave it with an appropriate file and settings.
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Ahhh….yes! I always forget to ask this. If it’s an Aura or Spark, neither one can do ANYthing with clear acrylic.
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I have a Glowforge Pro
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Great! Let’s get this sorted out.
Your pro can engrave all colors of acrylic. When you say it didn’t engrave at all, did the machine go through the motions of engraving but not burn away any material? If so, the problem could be a duplicated file. If two copies of a file are stacked on top of each other by accident, the Glowforge will act like it is engraving but the laser doesn’t actually fire.
Are you certain that Proofgrade settings were selected for the engrave operation? Sometimes the power setting resets to 0 and there will be no burning of the material.
Please print the Gift of Good Measure on one of the Amazon acrylics using the Medium Acrylic Proofgrade setting for a similar color of acrylic. Share the photo of your result and we can help you.
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Yes, the machine went through the motions but did not engrave. I will delete the file and reimport it and try again. The Glowforge did print a gift of good measure on proofgrade wood. I will try with some proofgrade acrylic.
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If it went through the motions without engraving, it is either an incorrect power setting or a stacked file. Either way, the machine is ok - which is good.
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It must be the files so I have contacted the vendor. Thank you
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It also fractures into sharp edges and pointy bits. Cast usually has dull edges & extruded has shiny edges. You can get shiny edges on your cast projects by flame treating them after cutting (washing the edge in a torch flame is quick & easy).
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Yeah, goood point extruded is a bit more prone to cracking and crazing.
But as a simple rectangle for like picture frame “glass” it’s functionally the same as cast. It’ll really depend on your project.
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