Hello, I am new to Blender…
I tried to make an inset on a curved surface. But somehow, it makes the surface looks ‘bumpy’.
Is it possible to make it neat and flat?
I tried to make it manually with knife tool. But it does not make it any better…
Thank you.
Hi,
While in edit mode, click RMB where you want to apply an inset, then LoopTools > Space
It has to do with how Smooth interpolation works. Divide a flat area into more faces and the surrounding edges become “sharper”.
This is not an entirely correct image, but I hope it relays the idea:
You can use Custom Normals.
For example transfer normals from smooth mesh onto one with inset.
However, this is probably only good for finished low poly meshes. Any further editing might disrupt and destroy the normal data 
Probably
Hello. Welcome to the BA Forums.
And then what happens after the inset? If you are making an inset, you are going to do something with the inset. Just carry on. Do not stop at each step and worry too much - its something most of us do when we start. 
Get the entire edit done in that area then go back and tidy up if needed.
Most of the time people will add a Subdivision Surface Modifier to smooth the model.
Thanks for your replies!
sorry, I am late for replying.
Yeah I sorted it out finally!
I found out about loop tools in this thread hahahah. But instead of using space as Sergey mentioned, I ended up using circle. Because I actually want it to be round. But, I didn’t know about Loop tools so I was using inset and subdivide the edges manually, it turns out terribly bumpy lol.
So I did the inset first, delete the faces, then I got square empty faces. Then I selected the edges, and using LoopTools → Circle
Still working on it. Thanks once again!! 
hahaha yes, I got confused for almost every step that I made 
will remember this, thanks!!
