You set the width as 0.5 – or to make it always 1 pixel then set it to (1.0 / [UIScreen mainScreen].scale)
I’ve done this before and it’s worked fine
I think the reason you can’t see it is that you are centering the line exactly in the middle of the screen, which will make the line’s origin (320 – 0.5) / 2.0, being an X origin of 159.75 – the 0.75 may be messing things up – or the cell is removing the background color of your view