Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Basic Pattern 2 No Background
Source GDJ
A seamless web texture of "green stone".
Source V. Hartikainen
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
A seamless pattern based on a tile that can be achieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
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
Feel free to download and use it, or see the rest of the dark background patterns that I have made. Anyway, I hope you will find something that you like.
Source V. Hartikainen
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
A heavy hitter at 400x400px, but lovely still.
Source Breezi
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
Remixed from a drawing in 'An Index to Deering's Nottinghamia Vetus et Nova', Rupert Chicken, 1899. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Prismatic Groovy Concentric Background 4
Source GDJ