A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Remixed from a JPG that was uploaded to Pixabay by Osckar
Source Firkin
Prismatic Abstract Geometric Background 5
Source GDJ
The image depicts a seamless pattern of Japanese Edo pattern called "kikkou-matsu" or "亀甲松" meaning " tortoiseshell-pinetree".The real pinetree is like this: https://jp.pinterest.com/pin/500744052301065077/
Source Yamachem
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
Same classic 45-degree pattern, dark version.
Source Luke McDonald
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
This background texture resembles stone. It may be used as a background on web pages or on some of their html elements (header, borders, menu bar, etc.). Just modify it for your needs.
Source V. Hartikainen
Adapted from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo