There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern formed from background pattern 102
Source Firkin
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
Prismatic Groovy Concentric Background 3
Source GDJ
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Seamless Dark Grunge Texture. Here's a new grunge texture for use as a background.
Source V. Hartikainen
Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
ZeroCC tileabel stone granite texture, edited from pixabay. CC0
Source Sojan Janso
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Wasn't satisfied with the original's colouring. Too much component transfer and colormatrixes yet the results are lacking a bit. So this time it is a simple black to transparent fade, making it possible remixing easily once there will be other blending modes supported as well. Probably in inkscape 0.92.
Source Lazur URH
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
This was formed by distorting an image of a background on Pixabay.
Source Firkin
This background pattern contains a seamless texture of bark. It's not very realistic, but I think it looks quite nice.
Source V. Hartikainen