Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
Prismatic Abstract Geometric Background 4
Source GDJ
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
A browner version of the original weathered fence texture.
Source Firkin
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless pattern of "sewn stripes" colored in light gray.
Source V. Hartikainen
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Looks as if it's spray painted on the wall. You can be sure that this pattern will seamlessly fill your backgrounds on web pages.
Source V. Hartikainen
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
Remixed from a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
This is the remix of "plant pattern 02".I changed the object color to white and the BG to purple.The image a seamless pattern derived from a weed which I can't identify.The original weed image is from here:jp.pinterest.com/pin/500744052301423641/
Source Yamachem
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
A nice looking light gray background pattern with diagonal stripes.
Source V. Hartikainen
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
Sometimes you just need the simplest thing.
Source Fabricio