Here's a seamless brown cork board background texture. Feel free to download or reshare if you like.
Source V. Hartikainen
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
The image depicts a Japanese Edo pattern called "kanoko or 鹿の子" meaning "fawn" which has a fur with small white spots.
Source Yamachem
Found on the ground in french cafe in kunming, Yunnan, china
Source Rejon
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
A seamlessly tileable pink background texture.
Source V. Hartikainen
Textured Red Brown Plastic, Free Background Pattern. Although there's already enough plastic in our lives, let's bring it to the web too.)
Source V. Hartikainen
The tile for this is based on a repeating unit close to a design on Pixabay. It can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen