What is this meant to be?

I was just running up to varrock from lumbridge on my new account when I noticed these strange black marks on every tile..

Note: You can only see them when you are on Mid or High graphics settings




What are they supposed to be?

 

Graphic glitch, change your Display mode to DirectX or OpenGL.

 

They're not Jagex messing with you, they're your computer messing with you.

Someone else had posted a similar glitch earlier.

 

Oh, right. I assumed it was part of the game as it wasn't everywhere, just in open spaces. Also, glitches tend to flash and/or flicker. This one was completely still.

 

Yeah, it's a graphic glitch.

 

Simply a glitch.