Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
It’s a hole, in a pattern. On your website. Dig it!
Source Josh Green
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
A new one called white wall, not by me this time.
Source Yuji Honzawa
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Non-seamless pattern drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
A seamless background colored in pale orange. It has a paper like texture with diagonal grid pattern.
Source V. Hartikainen
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
This tiled background comes in red and consists of tiles that look like gemstones. It is more for blogs or social profiles, I think.
Source V. Hartikainen
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Seamless Prismatic Quadrilateral Line Art Pattern No Background
Source GDJ
Seamless Olive Green Web Background Image
Source V. Hartikainen
The starting point for this was a texture drawn with the 'Radial Colors' plug-in in Paint.net.
Source Firkin
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica