A seamless background tile of aged paper with shabby look.
Source V. Hartikainen
A seamless background pattern with a texture of wood planks. This wood background pattern has vertically arranged planks. You may try to rotate it 90°, to see how it will look like when the wood planks are arranged horizontally.
Source V. Hartikainen
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Textured Red Brown Plastic, Free Background Pattern. Although there's already enough plastic in our lives, let's bring it to the web too.)
Source V. Hartikainen
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
Abstract Stars Geometric Pattern Prismatic No Background
Source GDJ
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Zero CC bark from fur tree tileable texture, photographed and made by me. CC0
Source Sojan Janso
Here's a bluish gray striped background pattern for use on web sites.
Source V. Hartikainen
Remixed from a drawing in 'Kulturgeschichte der Deutschen im Mittelalter' Franz von Loeher, 1891. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Inspired by a design found in 'Konstantinápolyi emlékeim', Miklos Chriszto, 1893.
Source Firkin
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
Alternative colour scheme. 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
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin