it’s definitely extruded, i used a lot of it (optix from HD) to make ear savers.
extruded is really bad for engraving.
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Sounds like you’ve hit the nail on the head! I will say, there are lots of places you can get acrylic online - many of which will be more trustworthy than Home Depot. You can do a search on here for “acrylic sources”. I generally go with TAP Plastics.
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Generally if it doesn’t say cast, it’s extruded. You’re not likely to see any that says it’s extruded but pretty much all cast says it’s cast. Cast is more expensive so it’s labeled to justify the extra expense.
In addition to all the other tests, extruded fractures with sharp edges & pointy shards.
BTW, watch out for Lexan (polycarbonate plastic) at Home Depot. They carry that too and it’s not something you want to cut or engrave. That’s a recipe for slaggy melty messes.
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Thanks…I learned that the hard way…it wasn’t pretty. 
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a very very rough rule (because there are exceptions), but generally cast acrylic comes with paper masking and a lot of extruded with plastic masking.
again, there are exceptions, but i would presume anything with plastic is extruded unless i had an MSDS that told me otherwise.
cast is almost always paper masked (almost). and some extruded is paper masked.
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In my experience, extruded is almost always masked with thin plastic and cast is almost always masked with paper.
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it’s not totally uncommon for extruded to have paper, though. i have a few stacks of smaller pieces of extruded with paper masking. that said, i haven’t seen cast with plastic (though not saying it’s impossible).
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Hello @Alteci,
I’m glad to see that the community was able to help you narrow down the issue. Since the issue looks to be with the material being used and not trouble with your Glowforge, I’m going to go ahead and move this thread to the Everything Else section of the forum, that way you all can continue your discussion.
Should you run into any issues with your Glowforge or Proofgrade materials, please let us know and we’ll be happy to help.
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That’s why I said…
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I had some material credit for the Trotec TroGlass color gloss. It’s sooooo vibrant and I love it! The website is an absolute nightmare at times but great acrylic.
I’ve also used Total Plastics for my current display project and they’ve got excellent service and amazing clear acrylic (haven’t tried the colored). Plus they cut to the size I need, so I paid way less and have next to no waste since the sheets I ordered are only .25" wider and longer than what I’m cutting.
I’ve also used TAP Plastics but can only speak to the beauty of the real and white acrylic I ordered from them.
You can even find cast acrylic from Etsy, which is where I ended up finding Total Plastics (always go to the direct source, haha). Lots of options for cast. You’re going to find the one you like the most C: have fun!
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If you’re in a major metro area just google plastic supply near you. Sign companies are also a good place to look for cut-offs and scrap at good prices.
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One thing I’ll add – most manufacturers, as far as I know, color code the masking for their acrylics. I won’t guarantee it’s consistent across all of them, but I know from scrounging the scrap bin at TAP Plastics that brown masking meant the acrylic was cast. FWIW. 
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I got curious and did some digging and almost all of the places I found said the same thing. If it’s got paper, it’s most likely cast. If it’s got plastic, it’s probably extruded. One exception seems to be mirrored acrylic where they all seemed to have plastic on the one (shiny) side only…
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I used some acrylic from HD and I’m almost positive is was the same stuff. It didn’t engrave well at all and really stunk, so I dug into it and discovered it was in fact extruded. But FWIW, I have some extruded that engraves really nicely. I know most of it doesn’t, but ya just never know. 
And sorry if this has been asked already, but did you remove the masking before you engraved it? I ask because it looks like there’s some clear masking left in the center of the “P”.
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Helpful for that identifying part!
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Yeah, I definitely have some paper coated acrylic that’s extruded (not from HD). I got it out of the scrap pile at a local plastics dealer. They’ll typically be your cheapest source and they will know whether it’s cast or extruded.
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I pulled that specific piece because that text showed clearly. I have about 20 pieces that are between 8x8 and 12x12 and that’s the only one with that text complete. Most don’t show it at all. Not sure how big the parent sheet is or how often it’s written on there.
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Yes and no…the clear masking is removed from our final product, but in the screen shots above, I just kept printing and testing and was not clearing all of the masking.
I’ve found a few acrylic suppliers in my area and will reach out to them, thank you.
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