How can I remove the lines around the edge of an object? I got a Minecraft rig which I want to have as a transparent image for a thumbnail. I always get these weird lines around the head (and sometimes on the rest of the rig as well), but I want to get rid of them as they don't look nice. I tried removing the lines in Photoshop, but that takes a lot of time.

Please have a look at the screenshot which has been attached to this post. How do I get rid of the lines around my Blender Minecraft rig? I'm a Blender beginner, so please send very clear and detailed instructions if you know the answer! :)

Thanks!

Problem occurs with:
- Windows 7 Pro 32-bits
- Windows 10 Pro 64-bits
- Blender 2.75a (also had the problem in previous versions)

Download link for .blend file:
https://mega.nz/#!LV4zAJ6a!SYgFytB9C92YXd5gNaH8C7m2fWys2e0AetcRpmFeTwc
It appears to be a UV layout problem - not enough margin between the UV islands, so color data is bleeding over. From what I can see of the UV texture on the right everything is just packed way to closely together. But maybe you can fix this by scaling the UV islands in a little, one-by-one. 

Instead of this...



More like this:



Also, to fix triangles like that one on the arm, enable Auto Smooth in the Mesh Context.



Update:

I looked at your .blend and it does appear that the UV layout is the problem.

Note how there is no margin between the islands.



In addition to that, there are parts of the layout that are doubled-up. This may or may not be intentional, but it means a texture in that region will show up on more than one place on the mesh.