This was formed by distorting an image of a background on Pixabay.
Source Firkin
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
A repeating background of beige (or is it more vanilla yellow) textured stripes. One more background with stripes.
Source V. Hartikainen
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Original seamless pattern with an Inkscape filter.
Source Firkin
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
A criss-cross pattern similar to one I saw mown into a sports field.
Source Firkin
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
The following repeating website background is colored in a blue gray color and resembles a concrete wall or something similar to it.
Source V. Hartikainen
A repeating background of thick textured paper. Actually, it turned out to look like something between a paper and fabric.
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
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
A black tile-able background with paper-like texture.
Source V. Hartikainen
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
The image is a remix of "edo pattern-samekomon".I changed the color of dots from black to white and added BG in light-brown.
Source Yamachem
A set of paper filters. The base texture is generated the same way, only the compositing mode is varied.
Source Lazur URH
A seamless pattern of "sewn stripes" colored in light gray.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso