Hi, Ive hit 2 snags, one is straight forward, the other is a mystery.

Im trying to create a cyborg. Using a clever technique of normal maps to create indents and raised bits...

So problem is:
1-Never used this 3d painting technique. Stretching? Am i missing something? i just place circles on head as a test and theres a lot a stretching? Is theres a guide to this technique? hacks? tips?

2-I can easily make out what the problem with the stretching is. But these jagged lines, both in indent and with the circles, im not getting why they are so jagged?

First thing to look at is the size of your texture.

Second is the Max Texture Size specified in the Preference settings:

---

Stretching?

You mean you want to place a circle over the head and retain a circular curve?
Then you are out of luck. Avatar UVs are certainly stretched.
Quick look at stretch paint in Blender reveals it (it should be solid blue, or at least color should be evenly distributed across the UV map):


As oppose to this unwrap for instance where stretching is minimal:



That means you generally would have a hard time using 2D paint programs to draw straight, or smoothly curved objects over the UV for texture.

So you need to use 3D paint apps for that. Cheapest (free) is Blender. More advanced 3Dcoat, Substance Painter... etc

Quick Blender example painting over the mesh.



This does reveal that you'd have to paint an *egg* (in Photoshop for instance) in order to get an even circle over the head.

Hey thanks, I will take a look at this

Hey thanks for explanation.

And for years i thought this was flattened so you could draw anything on the UVs (in the likes of photoshop)...

Ive been playing around with it on Photoshop. It is almost impossible to get anything looking correct

But the good news is by accident i discovered DECALS in SKIN GEN and this works EXACTLY like what you are doing in blender. 
You can make any piece of artwork flat and it moves it round the head. This is truly amazing.
The only downside is when u move it 0.01 (the smallest increment), it does jump quite a bit. Bit gutted, because placing decals right up against a feature on the face is near impossible

But overall, well happy to find this DECAL feature ....

Thanks once again for your feedback + detailed response

Sure, no problem.
Yes, decals are easiest way since you can scale (to overcome stretched UV to some degree) and move on the fly.
And yes, placement precision is really needs to be fixed. I have a ticket opened a while ago: https://www.reallusion.com/FeedBackTracker/Issue/We-need-at-least-3-decimal-places-for-offset-and-other-controls-in-Appearance-Editor
Hope they fix it in CC4..