Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
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
An alternative colour scheme for the original background.
Source Firkin
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
This seamless web background texture looks like gray stone. It's great for using as a background image on web pages, or on some of their elements. Anyway, I hope you will find use for it.
Source V. Hartikainen
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.
Source Firkin
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Prismatic Floral Background No Black
Source GDJ
A seamless texture of an abstract wall colored in shades of light orange brown.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Sometimes you just need the simplest thing.
Source Fabricio
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
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo