A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
A floral background formed from numerous clones of flower 117.
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Prismatic Polka Dots 3 No Background
Source GDJ
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
I scanned a paper coffee cup. You know, in case you need it.
Source Atle Mo
A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.
Source Josh Green
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A pattern formed from a squared tile. The tile can be accessed 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
This one is amazing, truly original. Go use it!
Source Viahorizon
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica