You have to fullview it (if your DA isn't as stupid as mine is at the moment) to actually see the lines, but i guess that's pretty obvious

These took ages to make (hence the title

). Started as lines made with a pen on small post-it notes while I was answering phones at work (I have a tendency to scribble while being on the phone

). Someone dared me to fill out an A3 sheet. I thought that was too big, but started on a A4 instead (I never really completed it, so I forgot to scan that one), after a while I got tired so I put the drawing away for a couple of months.
Then I felt like making more lines and decided on A5 instead; not too small, and not too big to be "impossible". Also started using two colours in stead of just one. I became completely hooked for a month or two, or maybe three... (don't really remember anymore the last half year has just flown past). Some days I made "many" lines, other days just a couple.
I finished one, and then I finished another one, and started on a third one where I did it a bit differently than the others (I'm not sure if you even notice, it's the one in the middle), and I started a fourth one, but by the time I got half way I was sick of drawing lines, but I think they are pretty cool, so I just had to upload them

I'm trying to think how I could make an effect like that in Illustrator, but I haven't a clue, really I think the only way to pull this off is how you did it.
Also tried for fun to see if I could manage to make it in illustrator, didn't work out too well
Yeah, I think whoever figures out how to do this in AI deserves a jam sandwich and a salute.