I have some strange result in the surface texture when I print object vertically long. As shown in the attached picture, there is strange texture for region of the object it begins at certain hight and it is for a while then stops and the rest of the print is with the same surface texture as with the one in the beginning.
Filament: PLA
If anyone has any idea or the same experience please give some suggestions 
Often these surface differences coincide with print speed and/or layer time changes and/or transitions of infill.
Within your slicer preview tab use color shemes for layer time, print speed,… and check if you can find significant changes in the area in question,
Thank you, you are correct, it is about the layer time. Do you know how to adjust the settings to fix that?
I cannot give you a silver bullet to resolve/improve that issue but you can try a lower print speed ( silent ), increase wall loops, thicker outer wall line width, infill type and density. The last three I bring up because I see infill read through all along that edge which makes the issue likely more apparent.
You could also try to reduce the nozzle temps for those layers but that will require that you add some Nozzle temp G-Code for the start and end layer of this section.
It’s either because layer time changes or because there are more perimeters or other features in that area.
When it comes to speed, just slow down so that it prints all outer walls at a constant speed.
The second issue can be alleviated by using the Outer-first wall order, like Outer-Inner, Inner-Outer-Inner (sandwich), but those two are bad for printing overhangs, or the hopefully coming Outer-Outer-Inner.
Thanks for the tips, I will try different options.
