Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Abstract Stars Geometric Pattern Prismatic No Background
Source GDJ
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.
Source Firkin
Background Wall, Art Abstract, white Well & CC0 texture.
Source Ractapopulous
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen
A seamless pale yellow paper background with a pattern of animal tracks.
Source V. Hartikainen
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin