How to make 3D prints look like they're NOT 3D printed.

Finishing techniques to make your 3D prints look amazing!

[JeremyBlackston]

I've recently been experimenting with Acrylic modeling paste. This stuff is THICK! However, it can be thinned with water. You can apply it with a brush easily. The real party trick is once its dry, to get some water and a low grit sanding sponge. The water will "re-activate" the paste a little allowing you to sand/move the putty around to smooth it further. Works pretty well and is less "chemically" to other options. Also, it sands REALLY well.

[calebb]

for note, i use to do bodywork all day everyday, mostly fiberglass

i HIGHLY recommend 3m goggle gear 500 safety goggles. Not only are they inexpensive, so everyone can get them, but the lens is also replaceable if you want to have back ups incase you break or scratch them, the gg 500 is D4 rated and should be more than enough here, but if you want to be extra sure go for the gg 2890 safety goggles that are D5 rated (fine dust), which are also over the glasses goggles for all you glasses needing folk

for the face masks/resperators my single use go to is the 3m specialty particulate respirators 8000, its an N95, P100, P95, R95 rated mask and worked quite well in my very dusty environment, and it had an breath exhalation valve so it didn't get too hot. for reusable resperators i very quickly fell in love with the half face rr 6300, as it could be set up for vapors and fumes like when i was painting cars, or dust of all types, it had replaceable cartridges so you just gotta pick the one that suits best for you

[peterkallend]

I recently printed something in a color I absolutely loved, so priming and painting weren't options. I knocked off the major surface blemishes with 100grit, evened out the surface with 250, then smoothed it out incrementally using 500 - 3000. It left a really cool, brushed finish Werth the layer lines looking like the grain of the material. To smooth it all out and make it all shiny, I used neutral shoe polish and basically spit shining the entire thing before sealing it a few coats of liquid floor polish. It's totally smooth, lost no detail, I can see my reflection in it, it smells surprisingly good, it's totally water proof and I didn't lose the color of the filament. I would definitely use this technique again, as the end result was definitely worth the time investment.

[sprNVA]

For anyone who wants to avoid the "orange peel" look after painting, you will need to wet-sand the paint. If you want to take it a step further and make the part look amazing, you can add clear coat, but you will - you guessed it - need to wet-sand to avoid orange peel. This definitely works best for larger surfaces, though. Since spraying paint and clear coat will fill in most fine details.

[incogneato]

There is a setting I've found really helps eliminate layer lines while printing. In Cura, under Walls, the Outer Wall Inset distance is the key. I set mine to 0.2mm and print at 0.12mm layer height and the results are very much like a resin print. You get better surface detail too.

[TheAruruu]

if you need a high gloss finish on a part, i STRONGLY recommend getting yourself the hobbyist set of MicroMesh pads. these things can take a print from looking like well... a painted piece of plastic, to looking like it's dyed glass. Best part is, unlike sand paper which can actually be quite aggressive in how much material it removes, MicroMesh is very gentle on the parts, so you can retain sharp edges.

[MarcsYoutube]

If you want your PLA parts to look and feel smooth, without loosing the initial material colour, here's what I do.
First I file down any rough spots and layer lines. Small metal files work quicker than sanding paper.
Once the part looks smoother, but still has medium to small imperfections, I coat it with a thin layer of CA glue. CA glue is inexpensive and dries quickly. Don't inhale the fumes!
Once dry, the CA glue layer needs to be sanded back almost completely, like you would automotive body filler. You can work your way up through the grits from 150 to 400 or even 600.
You'll be left with a super smooth, mat finish and the PLA colour is still very similar to how it was at the beginning.
If you want the part to be glossy or semi glossy, you can optionally spray-paint it with an appropriate transparent top coat.

[rynnjacobs]

Wet-sanding has advantages:
The water binds the dust and cools the object, so much more clean and no risk to soften PLA during sanding.

[KeithGroover]

For the parts I make, my preference is to use "fuzzy skin" on prusaslicer, then sand the part a little bit. It almost completely takes away the layer lines and makes it have a nice texture that feels like a sand-blasted injection molded part.

[DrGeta]

Another tip if you want to sand a print but don’t want to paint it and want to keep the original look of the filament you can rub Vaseline into the print where you have sanded and it will remove the white sanding marks back to original colour.

[DrGeta]

For TPU I can get rid of all layer lines by heating up some kind of rounded smooth clean metal like a screw driver. Heat it up to about 70 degrees on a stove or any heat source that does not make soot. And rub it back and forth over the print really REALLY fast. Like moving your arm back and forth 10 times a second. But just let the metal lightly rest on the TPU while it’s whipping back and forth. Feel the surface and see where it needs more smoothing in bursts of like 5 seconds on. 10 seconds off: it slowly melts the top layer completely smooth without changing its shape or anything. It really is just the layer lines that go and I print at 0.28.

[coffeefish]

A rule of thumb is to always use a lower grit before painting if your paint is thick, the paint will fill in the groves and leave a surface finish comprable to high grit, but it will stick much better. Generally you should only use a very high grit (>300) if you are going for a polish and not paint on top.

[cykubis]

If you have access to a sand blasting cabinet, blasting with soda is a phenomenal replacement to sanding. I use it particularly with resins, but it works great with PLA and PETG without the friction melting anything and gets into the nooks and crannies better than sanding ever can. Typically I just blast the model evenly for a few minutes then soak and rinse in water. Depending on the aesthetic I'm going for, I'll either hit it with clear coat for a gloss finish or I'll leave it as it and rub a tiny bit of WD-40 on it so the model keeps the texture but the WD-40 clears up the remaining whiting effect from blasting.

[davydatwood]

I build droids, and agree - if you want something to not look 3D printed, sand it smooth and paint it. A couple of tips to build on your suggestions:

-Print your parts with thicker walls if you're expecting to sand them. You need to have enough "meat" in there to sand it smooth. How thick those walls need to be depends on the accuracy of your printer, because a less accurate machine will need more sanding, but I'd suggest making sure you have at least 1.5mm to work with. On my parts I tend to be cautious and print with 2.4mm thick walls. (Also for strength.) Connected to the accuracy part, slowing your printer down so that it's more accurate will save a tonne of time sanding in the end.

-Spray paint is paint mixed with a solvent. Carrier solvents can have weird reactions with plastics. When you first use a new type of paint on a new type of plastic, TEST IT on scrap. It's unlikely in the modern world, but I have in the past had spray paints dissolve a piece of plastic, or just refuse to cure - I have a plastic ball I painted silver 20 years ago that *still* isn't fully cured and is tacky to the touch. A good layer of primer will usually avoid any problems, but better to test your paints than ruin your parts. (Layering paints from two different brands can also have weird effects and you should test that, too.)

-PLA is the most rigid plastic used on hobby printers, and consequently the most difficult to sand. ABS is relatively soft and much easier to sand. It's my experience that ABS is about half as much work to sand smooth as PLA is. So if you're doing a lot of parts that you're sanding and finishing, and you have a printer that will handle ABS reasonable well, it's worth the effort to learn to print it.

[tammasus]

I’ve been using sodium bicarbonate commonly used for removing smells in refrigerators with 3d resin to thicken it up. I got the idea from when I used it with crazy glue to make it harden faster.

[roofoofighter]

Wood filler is great for filling layer lines, it’s water based so it’s easy to clean up, dries fast, relatively cheap, and easy to sand to a smooth finish.

[kohtalaisenleveahomer]

Acrylic gesso can be a good option if you want a smooth surface quickly. The surface needs to be sanded rough first and I recommend water sanding. PLA in particular will clog the sandpaper in no time. If you use an ordinary brush to apply gesso, it is easy to leave brush marks. I don't know what the right word for the technique is, in Finnish it's called "töpöttäminen" but the idea is to stipple the surface with gesso. I recommend a foam brush or a wash sponge, a magic sponge gives an even finer texture. This leaves a smooth texture that can be sanded even smoother. Depending on how thick the gesso is, a few coats are enough and you can apply acrylic paint and acrylic varnish in the same way.

[AZREDFERN]

Most spray paints that advertise they work great on plastic, have a heavy acetone base (at least in the US). So any plastic that can be dissolved by acetone, like ABS, will not only get a great bond, but smooth and bulk up the surface slightly. It’s not effective on other plastics like PLA and PETG. It’ll still stick like paint. But you’re not getting the same bond and none of the smoothing.

[cameronrodwell]

Thankyou for doing this from an Aussie perspective it is nice to be able to find stuff in our country based off of what you are talking about.

[aaronalquiza]

i tried printing with translucent PETG and sanded up to 1000 grit and worked out pretty well. i also used a dremel in some areas for quicker sanding.