Sometimes you just need the simplest thing.
Source Fabricio
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
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A bit strange this one, but nice at the same time.
Source Diogo Silva
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
Used the 6th circle pattern designed by Viscious-Speed to create a print that can be used for card making or scrapbooking. Save as a PDF file for the best printing option.
Source Lovinglf
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Prismatic Abstract Geometric Background 2
Source GDJ
A dark metal plate with an embossed grid pattern and a bit of rust. Here's a dark metal plate texture for use as a tiled background on web pages.
Source V. Hartikainen
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin