A seamless pattern the starting point for which was a 'light rays' rendering in Paint.net.
Source Firkin
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
A slightly grainy paper pattern with small horizontal and vertical strokes.
Source Atle Mo
A seamless pattern of "sewn stripes" colored in light gray.
Source V. Hartikainen
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
A seamless background pattern of dark brown wood planks.
Source V. Hartikainen
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen
A green background pattern with warped vertical stripes and a grunge look.
Source V. Hartikainen
Zero CC tileable ground cracked, crackled, texture, made by me.
Source Sojan Janso
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
A seamless background texture of old cardboard.
Source V. Hartikainen
The original enhanced with some gradients.
Source Firkin
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin