This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Continuing the geometric trend, here is one more.
Source Mike Warner
Zero CC tileable brick texture, photographed and made by me. CC0
Source Sojan Janso
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.
Source Lazur URH
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
There are many carbon patterns, but this one is tiny.
Source Designova
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
Number 4 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
Feel free to download this "Dark Wood" background texture for your web site. The background tiles seamlessly!
Source V. Hartikainen
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ