Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
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
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
This is a remix of "geometrical pattern 01".
Source Yamachem
A background tile of dark textile. Made this a long time ago and just now decided to publish it.
Source V. Hartikainen
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
A browner version of the original weathered fence texture.
Source Firkin
Seamless Green Tile Background
Source V. Hartikainen
Redrawn based on a drawing in 'По Сѣверо-Западу Россіи' Konstantin Sluchevsky, 1897.
Source Firkin
Number five from the same submitter, makes my job easy.
Source Dima Shiper
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
Black paper texture, based on two different images.
Source Atle Mo
Based from Design Kindle
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics