This was formed by distorting an image of a background on Pixabay.
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
The name is totally random, but hey, it sounds good.
Source Atle Mo
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
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
Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
A colourful background drawn originally in paint.net and vectorised in Vector Magic.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
An alternative colour scheme for the original background.
Source Firkin