An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
The image a seamless pattern of a wire-mesh fence.I want you to use this pattern as a lower layer.
Source Yamachem
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
A seamless design of flowers remixed from a jpg on Pixabay by Prawny.
Source Firkin
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A free light orange brown wallpaper with vertical stripes designed for use as a tiled background on websites. An yet another background pattern with vertical stripes.
Source V. Hartikainen
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
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
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin