Clear Acrylic Engraving and Color Filling with No Frosted Background

Hello all!

I am working on a project where I would like to laser engrave text into clear acrylic and fill it in with paint. I am hoping for suggestions about how to best color fill laser engraved acrylic.

I am having a problem with the background of the engraved area being frosty, which is fine when I am filling with white but looks bad when you fill any other color. Does anyone have experience with color filling acrylic successfully?

In my research I have come across some possibilities. It seems like extruded acrylic engraves more clearly than cast, but in a video I saw it still seems like it is pretty frosty. I also have seen that some people have done out of focus printing to melt the acrylic making it more see through. Has anyone been successful with getting an engraving to be see through?

Another issue I am dealing with is using regular acrylic paints to fill my engravings, I am having trouble getting it to fill in correctly and sometimes when I sand it the paint comes out of the engraved part. Maybe I could try a deeper engrave or a different type of paint. I have seen that people recommend rub n buff paint for this use. I would ideally like the paint to fill all the way so it would be flush with the top.

Thanks for any advice!

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This might be one of the few times when you should look for extruded acrylic - it engraves clearer. It smells a bit worse according to some, but it’ll give you that look you’re going for, also defocusing your engrave by .25-.5 will smooth the lines, and lastly you can run a flame over it (carefully) to try to smooth the lines.

So yes - it sounds like you have some testing ahead of you!

Add paper masking on the acrylic before you cut it out (extruded generally comes with plastic masking, you’ll have to take that off)

As far as the paint coming out, I’d suggest a deeper engrave, and leave the masking on until after you’ve painted. Once it’s dry you can sand (or you can paint and then carefully remove the paper masking while it’s still damp to get a nice sharp edge). I’ve also had good luck using acrylic nail polish as my “paint” as it dries very tough!

Obviously if you try the flame route you’re going to want to be very careful of the paper masking.

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Have you tried filling it with colored UV resin? I only have clear resin right now, so I can’t test it, but I hate painting, especially with acrylic paint. I just make sure everything is masked really well and then I hit it with a shot of spray paint. But I don’t think I’ve ever painted engraved clear acrylic.

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I’ve tried it with clear (cast) but don’t have any photos of it. My most recent testing though was done on black acrylic and though pretty nice looking, I still find it a challenge to keep spray paint from seeping under the edges of the masking. The very last timeI tried it, I took someone’s suggestion to spray it first with coat of clear acrylic to sort of help keep the bleeding at bay…but, I’m not sure I could tell a difference.

These three were all spray painted red with the masking left intact.

The one on top and also on the right also had UV resin added on top of the paint.

This one was hand-painted and also had resin hand-applied on top of the paint.

Don’t know if I’ve helped in any way, but the questions being posed are all ones that I’ve had myself…and I’m still not finished testing various techniques.

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I always just apply a Krylon spray paint before unmasking and haven’t had any issues to date.

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Maybe don’t engrave at all? Score the text instead, use a weeding tool to remove the tape from the letters only, and spray Krylon Fusion paint over the masking. Once it’s dry, remove the rest of the masking.

If you use acrylic paints and fill a deep engrave, eventually that paint may shrink a bit and can flake out of the engraving. Especially if any are destined for an outdoor garden.

It’d require a bigger up-front investment in materials, but you can also buy 2-color acrylic to make stakes with colored text without any painting.

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I had a little luck today just with leaving the paper on, spray painting, and then leaving it on until dry. I also tried filling it with embossing powder and melting it with my torch on super low. It didn’t come too bad and if I had taken more time with it I’m sure it would have pretty good results. Using the torch is not recommended at all but you can use the suggested heat gun I’m sure.

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I use the out of focus trick often on engraved acrylic - it does smooth it out a lot.

My cleanest method is to have the text twice. The first gets engraved out of focus, but this leaves slightly ragged edges. The second text is scored and this cleans the edges up.

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You could also try carefully flooding just the engraved area with acetone, which dissolves acrylic and should turn all the frosty bits clear. Let dry completely then add whatever color you want.

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I am by NO means an expert, so please, someone correct me if I’m wrong, and please take my tip with a grain of salt. I haven’t made any projects with large spaces to fill in, but I experimented with the HD engrave option on clear PG acrylic, and the result was much smoother and took paint much better than the default (SD) option.
Best of luck and I hope you get the results you’re looking for :slight_smile:

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Makes sense - HD significantly increases the LPI so it melts the acrylic as it goes over closer together :slight_smile: I’m betting HD + defocused engrave might get you almost perfectly smooth. The tradeoff is, of course, time.

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Wow thank you all for the advice! I am going to test out all of these ideas and let you know what works

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After engraving, flood the engraved area with Weld-On #4 Acrylic Solvent Cement. Let soak for a minute or so, then dump the solvent into a collection container. The engraved surface will smooth and your paint will look much nicer.

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this can help with color bleeding in wood, as the clear fills and blocks the capillary action. Acrylic does not have this capillarity, so it’s not surprising that you didn’t see a difference.

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I tried embossing powder on acrylic just once…it eventually just separated from the piece.

Of course…that is right! It never even entered my head. Makes perfect sense.

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hmm I can’t even get it to scrape off with razor blade. I guess its all different depending on acrylic make up and maker of embossing powder.

would this affect the surrounding areas? I guess I could test it myself but was just wondering if you knew offhand.

You would definitely want to keep it only in the engraved areas.

With the scoring method, you don’t find the paint is very fragile and susceptible to scratching off the smooth surface? I’m thinking of doing this on the reverse side of smooth clear acrylic, but it seems to me it would be pretty easy to wipe off, just like you wipe off the excess on an engraved filling from the smooth surfaces. Do you seal it?