A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
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
This is a seamless pattern of a woody texture.The original image is here:https://pixabay.com/ja/users/ClassicallyPrinted-1302233/
Source Yamachem
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Snowflakes Pattern No Background
Source GDJ
Alternative colour scheme for the original floral pattern.
Source Firkin
Light and tiny, just the way you like it.
Source Rohit Arun Rao
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
This is the remix of an Openclipart clipart called "Maze" uploaded by "any_ono_mous".Thanks.This is a seamless pattern of a maze.
Source Yamachem
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Prismatic Groovy Concentric Background 3
Source GDJ
A tile-able background for websites with paper-like texture and a grid pattern layered on top of it.
Source V. Hartikainen
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
A seamless background pattern of dark brown wood planks.
Source V. Hartikainen
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
It’s big, it’s gradient—and it’s square.
Source Brankic1979
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin