Classic 45-degree pattern, light version.
Source Luke McDonald
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
ZeroCC tileable mossy (lichen) stone texture, edited from pixabay. CC0
Source Sojan Janso
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
Otis Ray Redding was an American soul singer-songwriter, record producer, arranger, and talent scout. So you know.
Source Thomas Myrman
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Remixed from a drawing in 'Jezebel's Daughter', Wilkie Collins 1880
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks.
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
A background pattern with wavy green vertical stripes. This one has green stripes on a white background. Download if you like it.
Source V. Hartikainen
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
A seamless pattern formed from miutopia's cakes on a tablecloth.
Source Firkin