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 seamless texture of worn out "cardboard".
Source V. Hartikainen
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
Remixed from a PNG that was uploaded to Pixabay by gingertea
Source Firkin
Prismatic Basic Pattern 2 No Background
Source GDJ
Black And White Floral Pattern Background Inverse
Source GDJ
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
Abstract Tiled Background Extended 8
Source GDJ
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin