Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Zero CC tileable pine bark texture, photographed and made by me. CC0
Source Sojan Janso
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
An alternative colour scheme to the original seamless pattern.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Subtle scratches on a light gray background.
Source Andrey Ovcharov
The following repeating website background is colored in a blue gray color and resembles a concrete wall or something similar to it.
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.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A brown metallic grid pattern layered on top of a dark fabric texture. It should look great when using as a tiled background on web pages, especially blogs.
Source V. Hartikainen
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Remixed from a drawing in 'Jezebel's Daughter', Wilkie Collins 1880
Source Firkin
Zero CC tileable ground cracked, crackled, texture, made by me.
Source Sojan Janso
Inspired by an image that was uploaded to Pixabay by geralt
Source Firkin
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
A repeating background with dark brown stone-like texture and abstract pattern that looks like tree trunks.
Source V. Hartikainen
This is a hot one. Small, sharp and unique.
Source GraphicsWall
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim