Prismatic Polka Dots Mark II No Background
Source GDJ
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Remixed from a drawing that was uploaded to Pixabay by DavidZydd
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Retro Circles Background 5 No Black
Source GDJ
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
Classic vertical lines, in all its subtlety.
Source Cody L
From a drawing in 'Line and form', Walter Crane, 1914.
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
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Prismatic Geometric Pattern Background
Source GDJ
The perfect pattern for all your blogs about type, or type-related matters.
Source Atle Mo
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
A bit of scratched up grayness. Always good.
Source Dmitry
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova