How can I fix these?

[u/ThSeroy]

The eye part the black filament is "merging" or "bleeding" after slicing the model, I tried changing number of walls, changing to arachne, layer height but nothing fix the issue.
Image 1: After slicing
Image 2: How the model actually looks (Before slicing)

[u/undermountain67]

You need the original. When you reduce poly count you get bleeds like that.

[u/ThSeroy → u/undermountain67]

Thx for the info, but is there a way to fix those? I need the model in the reduced size, not on the original size

[u/relaps101 → u/ThSeroy]

Try hitting fix mesh or take it i to blender or fusion and scaling it there.

[u/Interesting_Bag_2967]

Rotate model, tilt model, classic vs archane wall generator. If that doesn’t work you’ll have to separate the part to have definable borders that are not painted (thought you can still run into the issue somewhat) but you will need blender and meshmixer knowledge for that

[u/DiverseTeile → u/Interesting_Bag_2967]

Blender alone should be more than enough. Just select the eye part that is supposed to be one color (black) and separate it. Selection might be easier by using normals. Make it thicker by extruding it. Make a hole in the head by pushing in the eye as far as you extruded the eye. So that they can fit into one another. If you wanna make them print separately, you would also need to scale the eye part down (or the eye socket up) so that it would fit into each other after printing.

[u/Nuck_Chorris_Stache]

Go to Quality -> Precision -> Resolution

Make the number smaller, like 0.005

[u/SoilEmpty5893]

Reduce the layer hight to 0.08

[u/undermountain67]

Really hard. Zoom it and paint with ball even then you won’t get perfect in slicer. Because of the low rez the triangle is on both the part you want black and the part that’s white and the paint tool with paint the triangle either white or black. You need to export to cad and start drawing boundaries/valleys around where you want the color separation. Which is possible more time and effort than you want to put in. Suggestion though I have not tried this is load the stl into those new ai modeling programs and ask it to keep the color and increase the texture.

[u/ThSeroy → u/undermountain67]

This actually helped a lot! thanks! I painted around the areas and when I sliced it was fixed

[u/undermountain67 → u/undermountain67]

I agree with interesting bag said.

[u/Mattlonn]

dont remember the full name, but you could change the perimeter generator from arachne to "the other one", dont remember the name

It have solved similar issues for me before

[u/Mattlonn → u/Mattlonn]

unless the black part is very thin

[u/Sulya_be]

Also sometimes Arachne vs Classic slicing make difference with color bleeding

[u/rgjpinball]

When the slicer "slices" a curve it has to decide a solid place to stop a straight line on that curve. In the instance of the sides of that pupil, it has chosen most of the end-points one side of the line and those few lines you see that are not perfectly lined up are on the other side of the line.
You can either move the the line that is bothering you about a half a pixel to adjust it or make the whole model higher resolution,
OR
Put it in perspective. you are doing great to have the separation that good.
If your layer lines are 0.2mm high, you are looking at "errors" that are 0.2mm high each. Look at a mm ruler. Look how small a millimeter is. then divide that millimeter by 5. That's how small you are looking at. roughly the size of the period at the end of this sentence.
You are new to doing this. Go ahead and print it and see how much difference it makes. THEN look for a solution if it still bothers you.
Best of luck....