A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Spice up your next school project with this icon background.
Source Swetha
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
This ladies and gentlemen, is texturetastic! Love it.
Source Adam Pickering
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Fix side and a seamless pattern formed from circles.
Source SliverKnight
A black tile-able background with paper-like texture.
Source V. Hartikainen