From the photo, you can see the first 10 layers of the horse are so smooth, you can see the layer clearly. However after the first 10 layers, you can see its printed in a different style, I don’t know how to explain here, but photo speaks more than words.

Is there anyone know the reason behind it?

I’m using XYZ da vinvi 1.0 A with Slic3r.

layer height: 0.2

Try to lubricate the axis, it might have something to do with that. I had a similar problem, but in my case they were randomly placed, like vibrations. I tried lubricating and replacing the nozzle, and the problem was gone for a time. Sometimes it comes back though, and I’ve noticed that the lower the resolution, the more probable is this thing happening. Might be callibration as well, or a combination. Good luck.

Looks like your infill grid is showing through. What is happening is the first 10 layers are solid then the system switches to what looks like maybe a 10% infill. Increase the number of vertical shells to make the walls thicker and less likely to show the infill try 3 or 4. You could probably reduce the number of solid horizontal shells to 3 or 4 to save some material. The other setting you might consider adjusting is the infill percentage by making it a bit larger. That would give the outer walls a bit more support so you cannot see the structure inside.

Thanks for your reply,

What do you mean by “the lower the resolution”? the resolution in terms of??

Thanks for your reply,

Where is the setting in Slic3r to reduce the number of solid horizontal shells and increase the number of vertical shells?