From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The image depicts a seamless pattern of Japanese Edo pattern called "kikkou-matsu" or "亀甲松" meaning " tortoiseshell-pinetree".The real pinetree is like this: https://jp.pinterest.com/pin/500744052301065077/
Source Yamachem
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
A repeating background of thick textured paper. Actually, it turned out to look like something between a paper and fabric.
Source V. Hartikainen
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
A free background tile with a pattern of pink bump dots. This background tile is sweet! Moreover, it's designed for use as website backgrounds.
Source V. Hartikainen
Remixed from a drawing that was uploaded to Pixabay by DavidZydd
Source Firkin
Looks like an old rug or a computer chip.
Source Patutin Sergey
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
Green Web Background, Seamless tile.
Source V. Hartikainen
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
Sharp pixel pattern, just like the good old days.
Source Paridhi
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
Here's a new gray "fabric" pattern. Use it as backgrounds for websites or for other purposes.
Source V. Hartikainen
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Here's a tile-able wood background image for use in web design.
Source V. Hartikainen