How do I get a "blurry line" in gimp? This is a close up of a Pokémon (Teddiursa):



How do I achieve this same effect in GIMP- i.e. a line that is kind of blurry on the edges? I'm sure there's a term for this, and I'm sure there is a really easy solution- I'm just not sure what to google.

Note: I may have asked this on the wrong site (I just searched image in the bar and this site came up). If I did, feel free to redirect me to where I should ask!

Thanks in advance!
It's called anti-aliasing and happens when you low-pass filter your signal (image) and then decimate it (scale it down). Hence, the way to get this is take a large picture with sharp edges, and image->scale image, using anything but "None" as method. Alternatively, blur filter (==low pass) or selective blur will also do.