Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
More in the paper realm, this time with fibers.
Source Jorge Fuentes
A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
Background Wall, Art Abstract, Star Well & CC0 texture.
Source Ractapopulous
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
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
An aged paper background tile with smeared and pressed text.
Source V. Hartikainen
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
White handmade paper pattern with small bumps.
Source Marquis
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
Seamless tile drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Prismatic Geometric Pattern Background No Black
Source GDJ
Retro Circles Background 8 No Black
Source GDJ
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
A free web background image with a seamless concrete-like texture and an Indian-red color.
Source V. Hartikainen
This light blue background pattern is quite pleasing to the eye, it consists of a tiny rough grid pattern, which is seamless by design. That's it, if you like the color, you can use this seamless pattern in a web design without making any further modifications to it.
Source V. Hartikainen
Kaleidoscope Prismatic Abstract No Background
Source GDJ