I personally don't use Gimp, I don't know anything about it at all.
In Photoshop there are a few ways to get them smooth / anti-aliased.
1) Use the brush tool and not the pen or pencil, it is anti-aliased.
2) Use a filter called Gaussian Blur ( I use 0.3 ( 1/3rd of a pixel equivalent ))
3) Select size 2 if forced to use a pencil tool, then marquee the area outside the lines and use the Eraser tool over the lines. This is supposedly deleting things within the marquee (outside the lines), but it will partially delete the outer edges of the lines, essentially giving it ant-aliasing.
I personally don't use Gimp, I don't know anything about it at all.
In Photoshop there are a few ways to get them smooth / anti-aliased.
1) Use the brush tool and not the pen or pencil, it is anti-aliased.
2) Use a filter called Gaussian Blur ( I use 0.3 ( 1/3rd of a pixel equivalent ))
3) Select size 2 if forced to use a pencil tool, then marquee the area outside the lines and use the Eraser tool over the lines. This is supposedly deleting things within the marquee (outside the lines), but it will partially delete the outer edges of the lines, essentially giving it ant-aliasing.
Hyd yn oed er fy mod Cymraeg , dim ond yn siarad Saesneg, felly yr wyf yn gobeithio y bydd y cyfieithu yn gywir.