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
This one looks like a cork panel. Feel free to use it as a tiled background on your blog or website.
Source V. Hartikainen
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Colour version of the original seamless pattern.
Source Firkin
Zero CC bark from fur tree tileable texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
Floral patterns might not be the hottest thing right now, but you never know when you need it!
Source Lauren
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
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
Tiny little flowers growing on your screen. Nice, huh?
Source Themes Tube
Prismatic Abstract Line Art Pattern Background
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
From an image on opengameart.org shared by rubberduck.
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Prismatic Groovy Concentric Background 2
Source GDJ
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ