From an image on opengameart.org shared by rubberduck.
Source Firkin
Prismatic Groovy Concentric Background 2
Source GDJ
ZeroCC tileable beechwood wood texture, generated in Neo Texture Edit by me. CC0
Source Sojan Janso
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Thin lines, noise and texture creates this crisp dark denim pattern.
Source Marco Slooten
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
This texture looks like old leather. It should look great as a background on web pages.
Source V. Hartikainen
A free seamless texture of reptile skin colored in a dark brown color. As always, you may use it as a repeated background image in your web design works, or for any other purposes.
Source V. Hartikainen
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin