Looks as if it's spray painted on the wall. You can be sure that this pattern will seamlessly fill your backgrounds on web pages.
Source V. Hartikainen
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A heavy hitter at 400x400px, but lovely still.
Source Breezi
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
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 'Picturesque New Guinea', J Lindt, 1887.
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay