A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).
Source V. Hartikainen
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Prismatic Snowflakes Pattern No Background
Source GDJ
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
This ladies and gentlemen, is texturetastic! Love it.
Source Adam Pickering
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Remixed from a drawing in 'Incidents on a Journey through Nubia to Darfoor', F. Ensor, 1891.
Source Firkin
This light yellow background pattern consists of an irregular pattern of spots. Here's a light background pattern with yellowish tint.
Source V. Hartikainen
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Prismatic Groovy Concentric Background
Source GDJ
One more sharp little tile for you. Subtle circles this time.
Source Blunia
So tiny, just 7 by 7 pixels – but still so sexy. Ah yes.
Source Dmitriy Prodchenko
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
A tile-able background for websites with paper-like texture and a grid pattern layered on top of it.
Source V. Hartikainen
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
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