This was formed by distorting an image of a background on Pixabay.
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless paper background colored in pale yellow.
Source V. Hartikainen
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
f you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
A comeback for you: the popular Escheresque, now in black.
Source Patten
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
From a drawing in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
A seamless background pattern with a texture of wood planks. This wood background pattern has vertically arranged planks. You may try to rotate it 90°, to see how it will look like when the wood planks are arranged horizontally.
Source V. Hartikainen
The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
Seamless Green Tile Background
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Here's a dark background pattern that contains a steel grid pattern as a texture. Use it as a website background or for other purposes. It's free!
Source V. Hartikainen
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
This is the remix of an OCAL clipart called "Art Nouveau ornament" uploaded by "microcosme".Thanks.This is a seamless pattern of an Art Nouveau ornament.
Source Yamachem
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin