A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
This background pattern contains a seamless texture of bark. It's not very realistic, but I think it looks quite nice.
Source V. Hartikainen
Colored maple leaves scattered on a surface. This is tileable, so it can be used as a background or wallpaper.
Source Eady
Looks like an old wall. I guess that’s it then?
Source Viahorizon
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i
Source Firkin
From a drawing in 'La Principauté de Liège et les Pays-Bas au XVIe siècle', Société des Bibliophiles Liégeois ,1887.
Source Firkin
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
emixed from a JPG that was uploaded to Pixabay by Kyotime
Source Firkin
Derived from a drawing in 'The Murmur of the Shells', Samuel Cowen, 1879.
Source Firkin
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
Geometric triangles seem to be quite hot these days.
Source Pixeden
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
This is sort of fresh, but still feels a bit old school.
Source Martuchox