I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
From a drawing in 'Hundert Jahre in Wort und Bild', S. Stefan, 1899.
Source Firkin
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
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
Prismatic Abstract Geometric Background 4
Source GDJ
No, not the band but the pattern. Simple squares in gray tones, of course.
Source Atle Mo
The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer.
Source Haris Šumić
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Prismatic Abstract Line Art Pattern Background
Source GDJ
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
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
Sometimes you just need the simplest thing.
Source Fabricio
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin