Basing lines

Soooo, I've been sitting here, basing these lines for about 45 minutes now and it just occurred to me. Is there a better/faster way to base lines? I use GIMP and have been putting a base color under the lines and erasing it piece by piece all the way around which takes ages. What do you guys do? 

I use the select wand (?) tool to select all the area outside the lines and inverse it so only the part inside the lines are selected. Then I can’t color outside the lines :)

I am not sure if it is the same for gimp because I haven't used gimp in a while but what I do is use the wand tool and select outside the lines (where the background would be) and click ctrl+I or ctrl+shift+I or you can right click and select inverse. I can't remember which one it was. Hope this helps!

i literally cannot figure out how to inverse fffffff
update: figured out the inverse, but when i go to color i only color the lines themselves ughgh
update 2: guys i got it finally bless your souls

Last edited on 2018-06-24 at 17:19:34 by valencia