Which way to lay stair carpet (lines across or down...)?

[LONESOMESOUND]

Just a quick question... I have carpet that looks like this...

... which I intend to lay down my staircase. I just have one very simple question, namely whether I should lay it so the lines go down the stairs or whether they should run from side to side. (Oh, actually, I'd like to know your reasoning too). I've been recommended both, so have come to DIYNot for the definitive answer

Many thanks in advance...!

 

[Symo]

From the looks of your picture I'd say stripes down. But, there is also the question of pile direction.
The pile should "fall" down the stairs. Bit difficult with a loop pile like yours but worth doing properly as it will affect the wear on the nosings a lot.
Run your hand along the carpet, the direction which feels smoothest should go down the stairs.

Blimey, it's hard to describe this in words.

Symo

 

[carpetman]

the way the carpet should be laid is with the ribs running down the stairs