Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Zero CC tileable pine bark texture, photographed and made by me. CC0
Source Sojan Janso
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
Abstract Tiled Background Extended 10
Source GDJ
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
8 by 8 pixels, and just what the title says.
Source pixilated
Seamless Dark Grunge Texture. Here's a new grunge texture for use as a background.
Source V. Hartikainen
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I. Version with black background.
Source Firkin
Black brick wall pattern. Brick your site up!
Source Alex Parker
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow