After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Redrawn based on a drawing in 'По Сѣверо-Западу Россіи' Konstantin Sluchevsky, 1897.
Source Firkin
From a drawing in 'Prose and Verse ', William Linton, 1836.
Source Firkin
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Basket Fibers, Basket Texture, Braid Background style CC0 texture.
Source 1A-Photoshop
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen
Here I have tried to create something that would look like maple wood. Not sure how well it's turned out, but at least it looks like wood.
Source V. Hartikainen
The image depicts a Japanese Edo pattern called "kanoko or 鹿の子" meaning "fawn" which has a fur with small white spots.
Source Yamachem
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I. A version of the original with random colors.
Source Firkin